// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main_test

import (
	"bytes"
	"fmt"
	"go/build"
	"go/format"
	"internal/race"
	"internal/testenv"
	"io"
	"io/ioutil"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"runtime"
	"strconv"
	"strings"
	"testing"
	"time"
)

var (
	canRun  = true  // whether we can run go or ./testgo
	canRace = false // whether we can run the race detector
	canCgo  = false // whether we can use cgo

	exeSuffix string // ".exe" on Windows

	skipExternal = false // skip external tests
)

func init() {
	switch runtime.GOOS {
	case "android", "nacl":
		canRun = false
	case "darwin":
		switch runtime.GOARCH {
		case "arm", "arm64":
			canRun = false
		}
	case "linux":
		switch runtime.GOARCH {
		case "arm":
			// many linux/arm machines are too slow to run
			// the full set of external tests.
			skipExternal = true
		case "mips", "mipsle", "mips64", "mips64le":
			// Also slow.
			skipExternal = true
			if testenv.Builder() != "" {
				// On the builders, skip the cmd/go
				// tests. They're too slow and already
				// covered by other ports. There's
				// nothing os/arch specific in the
				// tests.
				canRun = false
			}
		}
	case "freebsd":
		switch runtime.GOARCH {
		case "arm":
			// many freebsd/arm machines are too slow to run
			// the full set of external tests.
			skipExternal = true
			canRun = false
		}
	case "windows":
		exeSuffix = ".exe"
	}
}

// The TestMain function creates a go command for testing purposes and
// deletes it after the tests have been run.
func TestMain(m *testing.M) {
	if canRun {
		args := []string{"build", "-tags", "testgo", "-o", "testgo" + exeSuffix}
		if race.Enabled {
			args = append(args, "-race")
		}
		out, err := exec.Command("go", args...).CombinedOutput()
		if err != nil {
			fmt.Fprintf(os.Stderr, "building testgo failed: %v\n%s", err, out)
			os.Exit(2)
		}

		if out, err := exec.Command("./testgo"+exeSuffix, "env", "CGO_ENABLED").Output(); err != nil {
			fmt.Fprintf(os.Stderr, "running testgo failed: %v\n", err)
			canRun = false
		} else {
			canCgo, err = strconv.ParseBool(strings.TrimSpace(string(out)))
			if err != nil {
				fmt.Fprintf(os.Stderr, "can't parse go env CGO_ENABLED output: %v\n", strings.TrimSpace(string(out)))
			}
		}

		switch runtime.GOOS {
		case "linux", "darwin", "freebsd", "windows":
			canRace = canCgo && runtime.GOARCH == "amd64"
		}
	}

	// Don't let these environment variables confuse the test.
	os.Unsetenv("GOBIN")
	os.Unsetenv("GOPATH")
	os.Unsetenv("GIT_ALLOW_PROTOCOL")
	if home, ccacheDir := os.Getenv("HOME"), os.Getenv("CCACHE_DIR"); home != "" && ccacheDir == "" {
		// On some systems the default C compiler is ccache.
		// Setting HOME to a non-existent directory will break
		// those systems.  Set CCACHE_DIR to cope.  Issue 17668.
		os.Setenv("CCACHE_DIR", filepath.Join(home, ".ccache"))
	}
	os.Setenv("HOME", "/test-go-home-does-not-exist")

	r := m.Run()

	if canRun {
		os.Remove("testgo" + exeSuffix)
	}

	os.Exit(r)
}

// The length of an mtime tick on this system. This is an estimate of
// how long we need to sleep to ensure that the mtime of two files is
// different.
// We used to try to be clever but that didn't always work (see golang.org/issue/12205).
var mtimeTick time.Duration = 1 * time.Second

// Manage a single run of the testgo binary.
type testgoData struct {
	t              *testing.T
	temps          []string
	wd             string
	env            []string
	tempdir        string
	ran            bool
	inParallel     bool
	stdout, stderr bytes.Buffer
}

// testgo sets up for a test that runs testgo.
func testgo(t *testing.T) *testgoData {
	testenv.MustHaveGoBuild(t)

	if skipExternal {
		t.Skip("skipping external tests on %s/%s", runtime.GOOS, runtime.GOARCH)
	}

	return &testgoData{t: t}
}

// must gives a fatal error if err is not nil.
func (tg *testgoData) must(err error) {
	if err != nil {
		tg.t.Fatal(err)
	}
}

// check gives a test non-fatal error if err is not nil.
func (tg *testgoData) check(err error) {
	if err != nil {
		tg.t.Error(err)
	}
}

// parallel runs the test in parallel by calling t.Parallel.
func (tg *testgoData) parallel() {
	if tg.ran {
		tg.t.Fatal("internal testsuite error: call to parallel after run")
	}
	if tg.wd != "" {
		tg.t.Fatal("internal testsuite error: call to parallel after cd")
	}
	for _, e := range tg.env {
		if strings.HasPrefix(e, "GOROOT=") || strings.HasPrefix(e, "GOPATH=") || strings.HasPrefix(e, "GOBIN=") {
			val := e[strings.Index(e, "=")+1:]
			if strings.HasPrefix(val, "testdata") || strings.HasPrefix(val, "./testdata") {
				tg.t.Fatalf("internal testsuite error: call to parallel with testdata in environment (%s)", e)
			}
		}
	}
	tg.inParallel = true
	tg.t.Parallel()
}

// pwd returns the current directory.
func (tg *testgoData) pwd() string {
	wd, err := os.Getwd()
	if err != nil {
		tg.t.Fatalf("could not get working directory: %v", err)
	}
	return wd
}

// cd changes the current directory to the named directory. Note that
// using this means that the test must not be run in parallel with any
// other tests.
func (tg *testgoData) cd(dir string) {
	if tg.inParallel {
		tg.t.Fatal("internal testsuite error: changing directory when running in parallel")
	}
	if tg.wd == "" {
		tg.wd = tg.pwd()
	}
	abs, err := filepath.Abs(dir)
	tg.must(os.Chdir(dir))
	if err == nil {
		tg.setenv("PWD", abs)
	}
}

// sleep sleeps for one tick, where a tick is a conservative estimate
// of how long it takes for a file modification to get a different
// mtime.
func (tg *testgoData) sleep() {
	time.Sleep(mtimeTick)
}

// setenv sets an environment variable to use when running the test go
// command.
func (tg *testgoData) setenv(name, val string) {
	if tg.inParallel && (name == "GOROOT" || name == "GOPATH" || name == "GOBIN") && (strings.HasPrefix(val, "testdata") || strings.HasPrefix(val, "./testdata")) {
		tg.t.Fatalf("internal testsuite error: call to setenv with testdata (%s=%s) after parallel", name, val)
	}
	tg.unsetenv(name)
	tg.env = append(tg.env, name+"="+val)
}

// unsetenv removes an environment variable.
func (tg *testgoData) unsetenv(name string) {
	if tg.env == nil {
		tg.env = append([]string(nil), os.Environ()...)
	}
	for i, v := range tg.env {
		if strings.HasPrefix(v, name+"=") {
			tg.env = append(tg.env[:i], tg.env[i+1:]...)
			break
		}
	}
}

// doRun runs the test go command, recording stdout and stderr and
// returning exit status.
func (tg *testgoData) doRun(args []string) error {
	if !canRun {
		panic("testgoData.doRun called but canRun false")
	}
	if tg.inParallel {
		for _, arg := range args {
			if strings.HasPrefix(arg, "testdata") || strings.HasPrefix(arg, "./testdata") {
				tg.t.Fatal("internal testsuite error: parallel run using testdata")
			}
		}
	}
	tg.t.Logf("running testgo %v", args)
	var prog string
	if tg.wd == "" {
		prog = "./testgo" + exeSuffix
	} else {
		prog = filepath.Join(tg.wd, "testgo"+exeSuffix)
	}
	cmd := exec.Command(prog, args...)
	tg.stdout.Reset()
	tg.stderr.Reset()
	cmd.Stdout = &tg.stdout
	cmd.Stderr = &tg.stderr
	cmd.Env = tg.env
	status := cmd.Run()
	if tg.stdout.Len() > 0 {
		tg.t.Log("standard output:")
		tg.t.Log(tg.stdout.String())
	}
	if tg.stderr.Len() > 0 {
		tg.t.Log("standard error:")
		tg.t.Log(tg.stderr.String())
	}
	tg.ran = true
	return status
}

// run runs the test go command, and expects it to succeed.
func (tg *testgoData) run(args ...string) {
	if status := tg.doRun(args); status != nil {
		tg.t.Logf("go %v failed unexpectedly: %v", args, status)
		tg.t.FailNow()
	}
}

// runFail runs the test go command, and expects it to fail.
func (tg *testgoData) runFail(args ...string) {
	if status := tg.doRun(args); status == nil {
		tg.t.Fatal("testgo succeeded unexpectedly")
	} else {
		tg.t.Log("testgo failed as expected:", status)
	}
}

// runGit runs a git command, and expects it to succeed.
func (tg *testgoData) runGit(dir string, args ...string) {
	cmd := exec.Command("git", args...)
	tg.stdout.Reset()
	tg.stderr.Reset()
	cmd.Stdout = &tg.stdout
	cmd.Stderr = &tg.stderr
	cmd.Dir = dir
	cmd.Env = tg.env
	status := cmd.Run()
	if tg.stdout.Len() > 0 {
		tg.t.Log("git standard output:")
		tg.t.Log(tg.stdout.String())
	}
	if tg.stderr.Len() > 0 {
		tg.t.Log("git standard error:")
		tg.t.Log(tg.stderr.String())
	}
	if status != nil {
		tg.t.Logf("git %v failed unexpectedly: %v", args, status)
		tg.t.FailNow()
	}
}

// getStdout returns standard output of the testgo run as a string.
func (tg *testgoData) getStdout() string {
	if !tg.ran {
		tg.t.Fatal("internal testsuite error: stdout called before run")
	}
	return tg.stdout.String()
}

// getStderr returns standard error of the testgo run as a string.
func (tg *testgoData) getStderr() string {
	if !tg.ran {
		tg.t.Fatal("internal testsuite error: stdout called before run")
	}
	return tg.stderr.String()
}

// doGrepMatch looks for a regular expression in a buffer, and returns
// whether it is found. The regular expression is matched against
// each line separately, as with the grep command.
func (tg *testgoData) doGrepMatch(match string, b *bytes.Buffer) bool {
	if !tg.ran {
		tg.t.Fatal("internal testsuite error: grep called before run")
	}
	re := regexp.MustCompile(match)
	for _, ln := range bytes.Split(b.Bytes(), []byte{'\n'}) {
		if re.Match(ln) {
			return true
		}
	}
	return false
}

// doGrep looks for a regular expression in a buffer and fails if it
// is not found. The name argument is the name of the output we are
// searching, "output" or "error".  The msg argument is logged on
// failure.
func (tg *testgoData) doGrep(match string, b *bytes.Buffer, name, msg string) {
	if !tg.doGrepMatch(match, b) {
		tg.t.Log(msg)
		tg.t.Logf("pattern %v not found in standard %s", match, name)
		tg.t.FailNow()
	}
}

// grepStdout looks for a regular expression in the test run's
// standard output and fails, logging msg, if it is not found.
func (tg *testgoData) grepStdout(match, msg string) {
	tg.doGrep(match, &tg.stdout, "output", msg)
}

// grepStderr looks for a regular expression in the test run's
// standard error and fails, logging msg, if it is not found.
func (tg *testgoData) grepStderr(match, msg string) {
	tg.doGrep(match, &tg.stderr, "error", msg)
}

// grepBoth looks for a regular expression in the test run's standard
// output or stand error and fails, logging msg, if it is not found.
func (tg *testgoData) grepBoth(match, msg string) {
	if !tg.doGrepMatch(match, &tg.stdout) && !tg.doGrepMatch(match, &tg.stderr) {
		tg.t.Log(msg)
		tg.t.Logf("pattern %v not found in standard output or standard error", match)
		tg.t.FailNow()
	}
}

// doGrepNot looks for a regular expression in a buffer and fails if
// it is found. The name and msg arguments are as for doGrep.
func (tg *testgoData) doGrepNot(match string, b *bytes.Buffer, name, msg string) {
	if tg.doGrepMatch(match, b) {
		tg.t.Log(msg)
		tg.t.Logf("pattern %v found unexpectedly in standard %s", match, name)
		tg.t.FailNow()
	}
}

// grepStdoutNot looks for a regular expression in the test run's
// standard output and fails, logging msg, if it is found.
func (tg *testgoData) grepStdoutNot(match, msg string) {
	tg.doGrepNot(match, &tg.stdout, "output", msg)
}

// grepStderrNot looks for a regular expression in the test run's
// standard error and fails, logging msg, if it is found.
func (tg *testgoData) grepStderrNot(match, msg string) {
	tg.doGrepNot(match, &tg.stderr, "error", msg)
}

// grepBothNot looks for a regular expression in the test run's
// standard output or stand error and fails, logging msg, if it is
// found.
func (tg *testgoData) grepBothNot(match, msg string) {
	if tg.doGrepMatch(match, &tg.stdout) || tg.doGrepMatch(match, &tg.stderr) {
		tg.t.Log(msg)
		tg.t.Fatalf("pattern %v found unexpectedly in standard output or standard error", match)
	}
}

// doGrepCount counts the number of times a regexp is seen in a buffer.
func (tg *testgoData) doGrepCount(match string, b *bytes.Buffer) int {
	if !tg.ran {
		tg.t.Fatal("internal testsuite error: doGrepCount called before run")
	}
	re := regexp.MustCompile(match)
	c := 0
	for _, ln := range bytes.Split(b.Bytes(), []byte{'\n'}) {
		if re.Match(ln) {
			c++
		}
	}
	return c
}

// grepCountBoth returns the number of times a regexp is seen in both
// standard output and standard error.
func (tg *testgoData) grepCountBoth(match string) int {
	return tg.doGrepCount(match, &tg.stdout) + tg.doGrepCount(match, &tg.stderr)
}

// creatingTemp records that the test plans to create a temporary file
// or directory. If the file or directory exists already, it will be
// removed. When the test completes, the file or directory will be
// removed if it exists.
func (tg *testgoData) creatingTemp(path string) {
	if filepath.IsAbs(path) && !strings.HasPrefix(path, tg.tempdir) {
		tg.t.Fatalf("internal testsuite error: creatingTemp(%q) with absolute path not in temporary directory", path)
	}
	// If we have changed the working directory, make sure we have
	// an absolute path, because we are going to change directory
	// back before we remove the temporary.
	if tg.wd != "" && !filepath.IsAbs(path) {
		path = filepath.Join(tg.pwd(), path)
	}
	tg.must(os.RemoveAll(path))
	tg.temps = append(tg.temps, path)
}

// makeTempdir makes a temporary directory for a run of testgo. If
// the temporary directory was already created, this does nothing.
func (tg *testgoData) makeTempdir() {
	if tg.tempdir == "" {
		var err error
		tg.tempdir, err = ioutil.TempDir("", "gotest")
		tg.must(err)
	}
}

// tempFile adds a temporary file for a run of testgo.
func (tg *testgoData) tempFile(path, contents string) {
	tg.makeTempdir()
	tg.must(os.MkdirAll(filepath.Join(tg.tempdir, filepath.Dir(path)), 0755))
	bytes := []byte(contents)
	if strings.HasSuffix(path, ".go") {
		formatted, err := format.Source(bytes)
		if err == nil {
			bytes = formatted
		}
	}
	tg.must(ioutil.WriteFile(filepath.Join(tg.tempdir, path), bytes, 0644))
}

// tempDir adds a temporary directory for a run of testgo.
func (tg *testgoData) tempDir(path string) {
	tg.makeTempdir()
	if err := os.MkdirAll(filepath.Join(tg.tempdir, path), 0755); err != nil && !os.IsExist(err) {
		tg.t.Fatal(err)
	}
}

// path returns the absolute pathname to file with the temporary
// directory.
func (tg *testgoData) path(name string) string {
	if tg.tempdir == "" {
		tg.t.Fatalf("internal testsuite error: path(%q) with no tempdir", name)
	}
	if name == "." {
		return tg.tempdir
	}
	return filepath.Join(tg.tempdir, name)
}

// mustExist fails if path does not exist.
func (tg *testgoData) mustExist(path string) {
	if _, err := os.Stat(path); err != nil {
		if os.IsNotExist(err) {
			tg.t.Fatalf("%s does not exist but should", path)
		}
		tg.t.Fatalf("%s stat failed: %v", path, err)
	}
}

// mustNotExist fails if path exists.
func (tg *testgoData) mustNotExist(path string) {
	if _, err := os.Stat(path); err == nil || !os.IsNotExist(err) {
		tg.t.Fatalf("%s exists but should not (%v)", path, err)
	}
}

// wantExecutable fails with msg if path is not executable.
func (tg *testgoData) wantExecutable(path, msg string) {
	if st, err := os.Stat(path); err != nil {
		if !os.IsNotExist(err) {
			tg.t.Log(err)
		}
		tg.t.Fatal(msg)
	} else {
		if runtime.GOOS != "windows" && st.Mode()&0111 == 0 {
			tg.t.Fatalf("binary %s exists but is not executable", path)
		}
	}
}

// wantArchive fails if path is not an archive.
func (tg *testgoData) wantArchive(path string) {
	f, err := os.Open(path)
	if err != nil {
		tg.t.Fatal(err)
	}
	buf := make([]byte, 100)
	io.ReadFull(f, buf)
	f.Close()
	if !bytes.HasPrefix(buf, []byte("!<arch>\n")) {
		tg.t.Fatalf("file %s exists but is not an archive", path)
	}
}

// isStale reports whether pkg is stale, and why
func (tg *testgoData) isStale(pkg string) (bool, string) {
	tg.run("list", "-f", "{{.Stale}}:{{.StaleReason}}", pkg)
	v := strings.TrimSpace(tg.getStdout())
	f := strings.SplitN(v, ":", 2)
	if len(f) == 2 {
		switch f[0] {
		case "true":
			return true, f[1]
		case "false":
			return false, f[1]
		}
	}
	tg.t.Fatalf("unexpected output checking staleness of package %v: %v", pkg, v)
	panic("unreachable")
}

// wantStale fails with msg if pkg is not stale.
func (tg *testgoData) wantStale(pkg, reason, msg string) {
	stale, why := tg.isStale(pkg)
	if !stale {
		tg.t.Fatal(msg)
	}
	if reason == "" && why != "" || !strings.Contains(why, reason) {
		tg.t.Errorf("wrong reason for Stale=true: %q, want %q", why, reason)
	}
}

// wantNotStale fails with msg if pkg is stale.
func (tg *testgoData) wantNotStale(pkg, reason, msg string) {
	stale, why := tg.isStale(pkg)
	if stale {
		tg.t.Fatal(msg)
	}
	if reason == "" && why != "" || !strings.Contains(why, reason) {
		tg.t.Errorf("wrong reason for Stale=false: %q, want %q", why, reason)
	}
}

// cleanup cleans up a test that runs testgo.
func (tg *testgoData) cleanup() {
	if tg.wd != "" {
		if err := os.Chdir(tg.wd); err != nil {
			// We are unlikely to be able to continue.
			fmt.Fprintln(os.Stderr, "could not restore working directory, crashing:", err)
			os.Exit(2)
		}
	}
	for _, path := range tg.temps {
		tg.check(os.RemoveAll(path))
	}
	if tg.tempdir != "" {
		tg.check(os.RemoveAll(tg.tempdir))
	}
}

// failSSH puts an ssh executable in the PATH that always fails.
// This is to stub out uses of ssh by go get.
func (tg *testgoData) failSSH() {
	wd, err := os.Getwd()
	if err != nil {
		tg.t.Fatal(err)
	}
	fail := filepath.Join(wd, "testdata/failssh")
	tg.setenv("PATH", fmt.Sprintf("%v%c%v", fail, filepath.ListSeparator, os.Getenv("PATH")))
}

func TestFileLineInErrorMessages(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("err.go", `package main; import "bar"`)
	path := tg.path("err.go")
	tg.runFail("run", path)
	shortPath := path
	if rel, err := filepath.Rel(tg.pwd(), path); err == nil && len(rel) < len(path) {
		shortPath = rel
	}
	tg.grepStderr("^"+regexp.QuoteMeta(shortPath)+":", "missing file:line in error message")
}

func TestProgramNameInCrashMessages(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("triv.go", `package main; func main() {}`)
	tg.runFail("build", "-ldflags", "-crash_for_testing", tg.path("triv.go"))
	tg.grepStderr(`[/\\]tool[/\\].*[/\\]link`, "missing linker name in error message")
}

func TestBrokenTestsWithoutTestFunctionsAllFail(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.runFail("test", "./testdata/src/badtest/...")
	tg.grepBothNot("^ok", "test passed unexpectedly")
	tg.grepBoth("FAIL.*badtest/badexec", "test did not run everything")
	tg.grepBoth("FAIL.*badtest/badsyntax", "test did not run everything")
	tg.grepBoth("FAIL.*badtest/badvar", "test did not run everything")
}

func TestGoBuildDashAInDevBranch(t *testing.T) {
	if testing.Short() {
		t.Skip("don't rebuild the standard library in short mode")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.run("install", "math") // should be up to date already but just in case
	tg.setenv("TESTGO_IS_GO_RELEASE", "0")
	tg.run("build", "-v", "-a", "math")
	tg.grepStderr("runtime", "testgo build -a math in dev branch DID NOT build runtime, but should have")

	// Everything is out of date. Rebuild to leave things in a better state.
	tg.run("install", "std")
}

func TestGoBuildDashAInReleaseBranch(t *testing.T) {
	if testing.Short() {
		t.Skip("don't rebuild the standard library in short mode")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.run("install", "math", "net/http") // should be up to date already but just in case
	tg.setenv("TESTGO_IS_GO_RELEASE", "1")
	tg.run("install", "-v", "-a", "math")
	tg.grepStderr("runtime", "testgo build -a math in release branch DID NOT build runtime, but should have")

	// Now runtime.a is updated (newer mtime), so everything would look stale if not for being a release.
	tg.run("build", "-v", "net/http")
	tg.grepStderrNot("strconv", "testgo build -v net/http in release branch with newer runtime.a DID build strconv but should not have")
	tg.grepStderrNot("golang.org/x/net/http2/hpack", "testgo build -v net/http in release branch with newer runtime.a DID build .../golang.org/x/net/http2/hpack but should not have")
	tg.grepStderrNot("net/http", "testgo build -v net/http in release branch with newer runtime.a DID build net/http but should not have")

	// Everything is out of date. Rebuild to leave things in a better state.
	tg.run("install", "std")
}

func TestNewReleaseRebuildsStalePackagesInGOPATH(t *testing.T) {
	if testing.Short() {
		t.Skip("don't rebuild the standard library in short mode")
	}

	tg := testgo(t)
	defer tg.cleanup()

	addNL := func(name string) (restore func()) {
		data, err := ioutil.ReadFile(name)
		if err != nil {
			t.Fatal(err)
		}
		old := data
		data = append(data, '\n')
		if err := ioutil.WriteFile(name, append(data, '\n'), 0666); err != nil {
			t.Fatal(err)
		}
		tg.sleep()
		return func() {
			if err := ioutil.WriteFile(name, old, 0666); err != nil {
				t.Fatal(err)
			}
		}
	}

	tg.setenv("TESTGO_IS_GO_RELEASE", "1")

	tg.tempFile("d1/src/p1/p1.go", `package p1`)
	tg.setenv("GOPATH", tg.path("d1"))
	tg.run("install", "-a", "p1")
	tg.wantNotStale("p1", "", "./testgo list claims p1 is stale, incorrectly")
	tg.sleep()

	// Changing mtime and content of runtime/internal/sys/sys.go
	// should have no effect: we're in a release, which doesn't rebuild
	// for general mtime or content changes.
	sys := runtime.GOROOT() + "/src/runtime/internal/sys/sys.go"
	restore := addNL(sys)
	defer restore()
	tg.wantNotStale("p1", "", "./testgo list claims p1 is stale, incorrectly, after updating runtime/internal/sys/sys.go")
	restore()
	tg.wantNotStale("p1", "", "./testgo list claims p1 is stale, incorrectly, after restoring runtime/internal/sys/sys.go")

	// But changing runtime/internal/sys/zversion.go should have an effect:
	// that's how we tell when we flip from one release to another.
	zversion := runtime.GOROOT() + "/src/runtime/internal/sys/zversion.go"
	restore = addNL(zversion)
	defer restore()
	tg.wantStale("p1", "build ID mismatch", "./testgo list claims p1 is NOT stale, incorrectly, after changing to new release")
	restore()
	tg.wantNotStale("p1", "", "./testgo list claims p1 is stale, incorrectly, after changing back to old release")
	addNL(zversion)
	tg.wantStale("p1", "build ID mismatch", "./testgo list claims p1 is NOT stale, incorrectly, after changing again to new release")
	tg.run("install", "p1")
	tg.wantNotStale("p1", "", "./testgo list claims p1 is stale after building with new release")

	// Restore to "old" release.
	restore()
	tg.wantStale("p1", "build ID mismatch", "./testgo list claims p1 is NOT stale, incorrectly, after changing to old release after new build")
	tg.run("install", "p1")
	tg.wantNotStale("p1", "", "./testgo list claims p1 is stale after building with old release")

	// Everything is out of date. Rebuild to leave things in a better state.
	tg.run("install", "std")
}

func TestGoListStandard(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.cd(runtime.GOROOT() + "/src")
	tg.run("list", "-f", "{{if not .Standard}}{{.ImportPath}}{{end}}", "./...")
	stdout := tg.getStdout()
	for _, line := range strings.Split(stdout, "\n") {
		if strings.HasPrefix(line, "_/") && strings.HasSuffix(line, "/src") {
			// $GOROOT/src shows up if there are any .go files there.
			// We don't care.
			continue
		}
		if line == "" {
			continue
		}
		t.Errorf("package in GOROOT not listed as standard: %v", line)
	}

	// Similarly, expanding std should include some of our vendored code.
	tg.run("list", "std", "cmd")
	tg.grepStdout("golang.org/x/net/http2/hpack", "list std cmd did not mention vendored hpack")
	tg.grepStdout("golang.org/x/arch/x86/x86asm", "list std cmd did not mention vendored x86asm")
}

func TestGoInstallCleansUpAfterGoBuild(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.tempFile("src/mycmd/main.go", `package main; func main(){}`)
	tg.setenv("GOPATH", tg.path("."))
	tg.cd(tg.path("src/mycmd"))

	doesNotExist := func(file, msg string) {
		if _, err := os.Stat(file); err == nil {
			t.Fatal(msg)
		} else if !os.IsNotExist(err) {
			t.Fatal(msg, "error:", err)
		}
	}

	tg.run("build")
	tg.wantExecutable("mycmd"+exeSuffix, "testgo build did not write command binary")
	tg.run("install")
	doesNotExist("mycmd"+exeSuffix, "testgo install did not remove command binary")
	tg.run("build")
	tg.wantExecutable("mycmd"+exeSuffix, "testgo build did not write command binary (second time)")
	// Running install with arguments does not remove the target,
	// even in the same directory.
	tg.run("install", "mycmd")
	tg.wantExecutable("mycmd"+exeSuffix, "testgo install mycmd removed command binary when run in mycmd")
	tg.run("build")
	tg.wantExecutable("mycmd"+exeSuffix, "testgo build did not write command binary (third time)")
	// And especially not outside the directory.
	tg.cd(tg.path("."))
	if data, err := ioutil.ReadFile("src/mycmd/mycmd" + exeSuffix); err != nil {
		t.Fatal("could not read file:", err)
	} else {
		if err := ioutil.WriteFile("mycmd"+exeSuffix, data, 0555); err != nil {
			t.Fatal("could not write file:", err)
		}
	}
	tg.run("install", "mycmd")
	tg.wantExecutable("src/mycmd/mycmd"+exeSuffix, "testgo install mycmd removed command binary from its source dir when run outside mycmd")
	tg.wantExecutable("mycmd"+exeSuffix, "testgo install mycmd removed command binary from current dir when run outside mycmd")
}

func TestGoInstallRebuildsStalePackagesInOtherGOPATH(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("d1/src/p1/p1.go", `package p1
		import "p2"
		func F() { p2.F() }`)
	tg.tempFile("d2/src/p2/p2.go", `package p2
		func F() {}`)
	sep := string(filepath.ListSeparator)
	tg.setenv("GOPATH", tg.path("d1")+sep+tg.path("d2"))
	tg.run("install", "p1")
	tg.wantNotStale("p1", "", "./testgo list claims p1 is stale, incorrectly")
	tg.wantNotStale("p2", "", "./testgo list claims p2 is stale, incorrectly")
	tg.sleep()
	if f, err := os.OpenFile(tg.path("d2/src/p2/p2.go"), os.O_WRONLY|os.O_APPEND, 0); err != nil {
		t.Fatal(err)
	} else if _, err = f.WriteString(`func G() {}`); err != nil {
		t.Fatal(err)
	} else {
		tg.must(f.Close())
	}
	tg.wantStale("p2", "newer source file", "./testgo list claims p2 is NOT stale, incorrectly")
	tg.wantStale("p1", "stale dependency", "./testgo list claims p1 is NOT stale, incorrectly")

	tg.run("install", "p1")
	tg.wantNotStale("p2", "", "./testgo list claims p2 is stale after reinstall, incorrectly")
	tg.wantNotStale("p1", "", "./testgo list claims p1 is stale after reinstall, incorrectly")
}

func TestGoInstallDetectsRemovedFiles(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("src/mypkg/x.go", `package mypkg`)
	tg.tempFile("src/mypkg/y.go", `package mypkg`)
	tg.tempFile("src/mypkg/z.go", `// +build missingtag

		package mypkg`)
	tg.setenv("GOPATH", tg.path("."))
	tg.run("install", "mypkg")
	tg.wantNotStale("mypkg", "", "./testgo list mypkg claims mypkg is stale, incorrectly")
	// z.go was not part of the build; removing it is okay.
	tg.must(os.Remove(tg.path("src/mypkg/z.go")))
	tg.wantNotStale("mypkg", "", "./testgo list mypkg claims mypkg is stale after removing z.go; should not be stale")
	// y.go was part of the package; removing it should be detected.
	tg.must(os.Remove(tg.path("src/mypkg/y.go")))
	tg.wantStale("mypkg", "build ID mismatch", "./testgo list mypkg claims mypkg is NOT stale after removing y.go; should be stale")
}

func TestWildcardMatchesSyntaxErrorDirs(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.tempFile("src/mypkg/x.go", `package mypkg`)
	tg.tempFile("src/mypkg/y.go", `pkg mypackage`)
	tg.setenv("GOPATH", tg.path("."))
	tg.cd(tg.path("src/mypkg"))
	tg.runFail("list", "./...")
	tg.runFail("build", "./...")
	tg.runFail("install", "./...")
}

func TestGoListWithTags(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.tempFile("src/mypkg/x.go", "// +build thetag\n\npackage mypkg\n")
	tg.setenv("GOPATH", tg.path("."))
	tg.cd(tg.path("./src"))
	tg.run("list", "-tags=thetag", "./my...")
	tg.grepStdout("mypkg", "did not find mypkg")
}

func TestGoInstallErrorOnCrossCompileToBin(t *testing.T) {
	if testing.Short() {
		t.Skip("don't install into GOROOT in short mode")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.tempFile("src/mycmd/x.go", `package main
		func main() {}`)
	tg.setenv("GOPATH", tg.path("."))
	tg.cd(tg.path("src/mycmd"))

	tg.run("build", "mycmd")

	goarch := "386"
	if runtime.GOARCH == "386" {
		goarch = "amd64"
	}
	tg.setenv("GOOS", "linux")
	tg.setenv("GOARCH", goarch)
	tg.run("install", "mycmd")
	tg.setenv("GOBIN", tg.path("."))
	tg.runFail("install", "mycmd")
	tg.run("install", "cmd/pack")
}

func TestGoInstallDetectsRemovedFilesInPackageMain(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("src/mycmd/x.go", `package main
		func main() {}`)
	tg.tempFile("src/mycmd/y.go", `package main`)
	tg.tempFile("src/mycmd/z.go", `// +build missingtag

		package main`)
	tg.setenv("GOPATH", tg.path("."))
	tg.run("install", "mycmd")
	tg.wantNotStale("mycmd", "", "./testgo list mypkg claims mycmd is stale, incorrectly")
	// z.go was not part of the build; removing it is okay.
	tg.must(os.Remove(tg.path("src/mycmd/z.go")))
	tg.wantNotStale("mycmd", "", "./testgo list mycmd claims mycmd is stale after removing z.go; should not be stale")
	// y.go was part of the package; removing it should be detected.
	tg.must(os.Remove(tg.path("src/mycmd/y.go")))
	tg.wantStale("mycmd", "build ID mismatch", "./testgo list mycmd claims mycmd is NOT stale after removing y.go; should be stale")
}

func testLocalRun(tg *testgoData, exepath, local, match string) {
	out, err := exec.Command(exepath).Output()
	if err != nil {
		tg.t.Fatalf("error running %v: %v", exepath, err)
	}
	if !regexp.MustCompile(match).Match(out) {
		tg.t.Log(string(out))
		tg.t.Errorf("testdata/%s/easy.go did not generate expected output", local)
	}
}

func testLocalEasy(tg *testgoData, local string) {
	exepath := "./easy" + exeSuffix
	tg.creatingTemp(exepath)
	tg.run("build", "-o", exepath, filepath.Join("testdata", local, "easy.go"))
	testLocalRun(tg, exepath, local, `(?m)^easysub\.Hello`)
}

func testLocalEasySub(tg *testgoData, local string) {
	exepath := "./easysub" + exeSuffix
	tg.creatingTemp(exepath)
	tg.run("build", "-o", exepath, filepath.Join("testdata", local, "easysub", "main.go"))
	testLocalRun(tg, exepath, local, `(?m)^easysub\.Hello`)
}

func testLocalHard(tg *testgoData, local string) {
	exepath := "./hard" + exeSuffix
	tg.creatingTemp(exepath)
	tg.run("build", "-o", exepath, filepath.Join("testdata", local, "hard.go"))
	testLocalRun(tg, exepath, local, `(?m)^sub\.Hello`)
}

func testLocalInstall(tg *testgoData, local string) {
	tg.runFail("install", filepath.Join("testdata", local, "easy.go"))
}

func TestLocalImportsEasy(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	testLocalEasy(tg, "local")
}

func TestLocalImportsEasySub(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	testLocalEasySub(tg, "local")
}

func TestLocalImportsHard(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	testLocalHard(tg, "local")
}

func TestLocalImportsGoInstallShouldFail(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	testLocalInstall(tg, "local")
}

const badDirName = `#$%:, &()*;<=>?\^{}`

func copyBad(tg *testgoData) {
	if runtime.GOOS == "windows" {
		tg.t.Skipf("skipping test because %q is an invalid directory name", badDirName)
	}

	tg.must(filepath.Walk("testdata/local",
		func(path string, info os.FileInfo, err error) error {
			if err != nil {
				return err
			}
			if info.IsDir() {
				return nil
			}
			var data []byte
			data, err = ioutil.ReadFile(path)
			if err != nil {
				return err
			}
			newpath := strings.Replace(path, "local", badDirName, 1)
			tg.tempFile(newpath, string(data))
			return nil
		}))
	tg.cd(tg.path("."))
}

func TestBadImportsEasy(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	copyBad(tg)
	testLocalEasy(tg, badDirName)
}

func TestBadImportsEasySub(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	copyBad(tg)
	testLocalEasySub(tg, badDirName)
}

func TestBadImportsHard(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	copyBad(tg)
	testLocalHard(tg, badDirName)
}

func TestBadImportsGoInstallShouldFail(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	copyBad(tg)
	testLocalInstall(tg, badDirName)
}

func TestInternalPackagesInGOROOTAreRespected(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.runFail("build", "-v", "./testdata/testinternal")
	tg.grepBoth(`testinternal(\/|\\)p\.go\:3\:8\: use of internal package not allowed`, "wrong error message for testdata/testinternal")
}

func TestInternalPackagesOutsideGOROOTAreRespected(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.runFail("build", "-v", "./testdata/testinternal2")
	tg.grepBoth(`testinternal2(\/|\\)p\.go\:3\:8\: use of internal package not allowed`, "wrote error message for testdata/testinternal2")
}

func TestRunInternal(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	dir := filepath.Join(tg.pwd(), "testdata")
	tg.setenv("GOPATH", dir)
	tg.run("run", filepath.Join(dir, "src/run/good.go"))
	tg.runFail("run", filepath.Join(dir, "src/run/bad.go"))
	tg.grepStderr(`testdata(\/|\\)src(\/|\\)run(\/|\\)bad\.go\:3\:8\: use of internal package not allowed`, "unexpected error for run/bad.go")
}

func testMove(t *testing.T, vcs, url, base, config string) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("src")
	tg.setenv("GOPATH", tg.path("."))
	tg.run("get", "-d", url)
	tg.run("get", "-d", "-u", url)
	switch vcs {
	case "svn":
		// SVN doesn't believe in text files so we can't just edit the config.
		// Check out a different repo into the wrong place.
		tg.must(os.RemoveAll(tg.path("src/code.google.com/p/rsc-svn")))
		tg.run("get", "-d", "-u", "code.google.com/p/rsc-svn2/trunk")
		tg.must(os.Rename(tg.path("src/code.google.com/p/rsc-svn2"), tg.path("src/code.google.com/p/rsc-svn")))
	default:
		path := tg.path(filepath.Join("src", config))
		data, err := ioutil.ReadFile(path)
		tg.must(err)
		data = bytes.Replace(data, []byte(base), []byte(base+"XXX"), -1)
		tg.must(ioutil.WriteFile(path, data, 0644))
	}
	if vcs == "git" {
		// git will ask for a username and password when we
		// run go get -d -f -u. An empty username and
		// password will work. Prevent asking by setting
		// GIT_ASKPASS.
		tg.creatingTemp("sink" + exeSuffix)
		tg.tempFile("src/sink/sink.go", `package main; func main() {}`)
		tg.run("build", "-o", "sink"+exeSuffix, "sink")
		tg.setenv("GIT_ASKPASS", filepath.Join(tg.pwd(), "sink"+exeSuffix))
	}
	tg.runFail("get", "-d", "-u", url)
	tg.grepStderr("is a custom import path for", "go get -d -u "+url+" failed for wrong reason")
	tg.runFail("get", "-d", "-f", "-u", url)
	tg.grepStderr("validating server certificate|[nN]ot [fF]ound", "go get -d -f -u "+url+" failed for wrong reason")
}

func TestInternalPackageErrorsAreHandled(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("list", "./testdata/testinternal3")
}

func TestInternalCache(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata/testinternal4"))
	tg.runFail("build", "p")
	tg.grepStderr("internal", "did not fail to build p")
}

func TestMoveGit(t *testing.T) {
	testMove(t, "git", "rsc.io/pdf", "pdf", "rsc.io/pdf/.git/config")
}

func TestMoveHG(t *testing.T) {
	testMove(t, "hg", "vcs-test.golang.org/go/custom-hg-hello", "custom-hg-hello", "vcs-test.golang.org/go/custom-hg-hello/.hg/hgrc")
}

// TODO(rsc): Set up a test case on SourceForge (?) for svn.
// func testMoveSVN(t *testing.T) {
//	testMove(t, "svn", "code.google.com/p/rsc-svn/trunk", "-", "-")
// }

func TestImportCommandMatch(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata/importcom"))
	tg.run("build", "./testdata/importcom/works.go")
}

func TestImportCommentMismatch(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata/importcom"))
	tg.runFail("build", "./testdata/importcom/wrongplace.go")
	tg.grepStderr(`wrongplace expects import "my/x"`, "go build did not mention incorrect import")
}

func TestImportCommentSyntaxError(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata/importcom"))
	tg.runFail("build", "./testdata/importcom/bad.go")
	tg.grepStderr("cannot parse import comment", "go build did not mention syntax error")
}

func TestImportCommentConflict(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata/importcom"))
	tg.runFail("build", "./testdata/importcom/conflict.go")
	tg.grepStderr("found import comments", "go build did not mention comment conflict")
}

// cmd/go: custom import path checking should not apply to Go packages without import comment.
func TestIssue10952(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	if _, err := exec.LookPath("git"); err != nil {
		t.Skip("skipping because git binary not found")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("src")
	tg.setenv("GOPATH", tg.path("."))
	const importPath = "github.com/zombiezen/go-get-issue-10952"
	tg.run("get", "-d", "-u", importPath)
	repoDir := tg.path("src/" + importPath)
	tg.runGit(repoDir, "remote", "set-url", "origin", "https://"+importPath+".git")
	tg.run("get", "-d", "-u", importPath)
}

func TestIssue16471(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	if _, err := exec.LookPath("git"); err != nil {
		t.Skip("skipping because git binary not found")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("src")
	tg.setenv("GOPATH", tg.path("."))
	tg.must(os.MkdirAll(tg.path("src/rsc.io/go-get-issue-10952"), 0755))
	tg.runGit(tg.path("src/rsc.io"), "clone", "https://github.com/zombiezen/go-get-issue-10952")
	tg.runFail("get", "-u", "rsc.io/go-get-issue-10952")
	tg.grepStderr("rsc.io/go-get-issue-10952 is a custom import path for https://github.com/rsc/go-get-issue-10952, but .* is checked out from https://github.com/zombiezen/go-get-issue-10952", "did not detect updated import path")
}

// Test git clone URL that uses SCP-like syntax and custom import path checking.
func TestIssue11457(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	if _, err := exec.LookPath("git"); err != nil {
		t.Skip("skipping because git binary not found")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("src")
	tg.setenv("GOPATH", tg.path("."))
	const importPath = "rsc.io/go-get-issue-11457"
	tg.run("get", "-d", "-u", importPath)
	repoDir := tg.path("src/" + importPath)
	tg.runGit(repoDir, "remote", "set-url", "origin", "git@github.com:rsc/go-get-issue-11457")

	// At this time, custom import path checking compares remotes verbatim (rather than
	// just the host and path, skipping scheme and user), so we expect go get -u to fail.
	// However, the goal of this test is to verify that gitRemoteRepo correctly parsed
	// the SCP-like syntax, and we expect it to appear in the error message.
	tg.runFail("get", "-d", "-u", importPath)
	want := " is checked out from ssh://git@github.com/rsc/go-get-issue-11457"
	if !strings.HasSuffix(strings.TrimSpace(tg.getStderr()), want) {
		t.Error("expected clone URL to appear in stderr")
	}
}

func TestGetGitDefaultBranch(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	if _, err := exec.LookPath("git"); err != nil {
		t.Skip("skipping because git binary not found")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("src")
	tg.setenv("GOPATH", tg.path("."))

	// This repo has two branches, master and another-branch.
	// The another-branch is the default that you get from 'git clone'.
	// The go get command variants should not override this.
	const importPath = "github.com/rsc/go-get-default-branch"

	tg.run("get", "-d", importPath)
	repoDir := tg.path("src/" + importPath)
	tg.runGit(repoDir, "branch", "--contains", "HEAD")
	tg.grepStdout(`\* another-branch`, "not on correct default branch")

	tg.run("get", "-d", "-u", importPath)
	tg.runGit(repoDir, "branch", "--contains", "HEAD")
	tg.grepStdout(`\* another-branch`, "not on correct default branch")
}

func TestAccidentalGitCheckout(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	if _, err := exec.LookPath("git"); err != nil {
		t.Skip("skipping because git binary not found")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("src")
	tg.setenv("GOPATH", tg.path("."))

	tg.runFail("get", "-u", "vcs-test.golang.org/go/test1-svn-git")
	tg.grepStderr("src[\\\\/]vcs-test.* uses git, but parent .*src[\\\\/]vcs-test.* uses svn", "get did not fail for right reason")

	tg.runFail("get", "-u", "vcs-test.golang.org/go/test2-svn-git/test2main")
	tg.grepStderr("src[\\\\/]vcs-test.* uses git, but parent .*src[\\\\/]vcs-test.* uses svn", "get did not fail for right reason")
}

func TestErrorMessageForSyntaxErrorInTestGoFileSaysFAIL(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("test", "syntaxerror")
	tg.grepStderr("FAIL", "go test did not say FAIL")
}

func TestWildcardsDoNotLookInUselessDirectories(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("list", "...")
	tg.grepBoth("badpkg", "go list ... failure does not mention badpkg")
	tg.run("list", "m...")
}

func TestRelativeImportsGoTest(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "./testdata/testimport")
}

func TestRelativeImportsGoTestDashI(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "-i", "./testdata/testimport")
}

func TestRelativeImportsInCommandLinePackage(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	files, err := filepath.Glob("./testdata/testimport/*.go")
	tg.must(err)
	tg.run(append([]string{"test"}, files...)...)
}

func TestNonCanonicalImportPaths(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("build", "canonical/d")
	tg.grepStderr("package canonical/d", "did not report canonical/d")
	tg.grepStderr("imports canonical/b", "did not report canonical/b")
	tg.grepStderr("imports canonical/a/: non-canonical", "did not report canonical/a/")
}

func TestVersionControlErrorMessageIncludesCorrectDirectory(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata/shadow/root1"))
	tg.runFail("get", "-u", "foo")

	// TODO(iant): We should not have to use strconv.Quote here.
	// The code in vcs.go should be changed so that it is not required.
	quoted := strconv.Quote(filepath.Join("testdata", "shadow", "root1", "src", "foo"))
	quoted = quoted[1 : len(quoted)-1]

	tg.grepStderr(regexp.QuoteMeta(quoted), "go get -u error does not mention shadow/root1/src/foo")
}

func TestInstallFailsWithNoBuildableFiles(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.setenv("CGO_ENABLED", "0")
	tg.runFail("install", "cgotest")
	tg.grepStderr("no buildable Go source files", "go install cgotest did not report 'no buildable Go Source files'")
}

func TestRelativeGOBINFail(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.tempFile("triv.go", `package main; func main() {}`)
	tg.setenv("GOBIN", ".")
	tg.runFail("install")
	tg.grepStderr("cannot install, GOBIN must be an absolute path", "go install must fail if $GOBIN is a relative path")
}

// Test that without $GOBIN set, binaries get installed
// into the GOPATH bin directory.
func TestInstallIntoGOPATH(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.creatingTemp("testdata/bin/go-cmd-test" + exeSuffix)
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.run("install", "go-cmd-test")
	tg.wantExecutable("testdata/bin/go-cmd-test"+exeSuffix, "go install go-cmd-test did not write to testdata/bin/go-cmd-test")
}

// Issue 12407
func TestBuildOutputToDevNull(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.run("build", "-o", os.DevNull, "go-cmd-test")
}

func TestPackageMainTestImportsArchiveNotBinary(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	gobin := filepath.Join(tg.pwd(), "testdata", "bin")
	tg.creatingTemp(gobin)
	tg.setenv("GOBIN", gobin)
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.must(os.Chtimes("./testdata/src/main_test/m.go", time.Now(), time.Now()))
	tg.sleep()
	tg.run("test", "main_test")
	tg.run("install", "main_test")
	tg.wantNotStale("main_test", "", "after go install, main listed as stale")
	tg.run("test", "main_test")
}

// The runtime version string takes one of two forms:
// "go1.X[.Y]" for Go releases, and "devel +hash" at tip.
// Determine whether we are in a released copy by
// inspecting the version.
var isGoRelease = strings.HasPrefix(runtime.Version(), "go1")

// Issue 12690
func TestPackageNotStaleWithTrailingSlash(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()

	// Make sure the packages below are not stale.
	tg.run("install", "runtime", "os", "io")

	goroot := runtime.GOROOT()
	tg.setenv("GOROOT", goroot+"/")

	want := ""
	if isGoRelease {
		want = "standard package in Go release distribution"
	}

	tg.wantNotStale("runtime", want, "with trailing slash in GOROOT, runtime listed as stale")
	tg.wantNotStale("os", want, "with trailing slash in GOROOT, os listed as stale")
	tg.wantNotStale("io", want, "with trailing slash in GOROOT, io listed as stale")
}

// With $GOBIN set, binaries get installed to $GOBIN.
func TestInstallIntoGOBIN(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	gobin := filepath.Join(tg.pwd(), "testdata", "bin1")
	tg.creatingTemp(gobin)
	tg.setenv("GOBIN", gobin)
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.run("install", "go-cmd-test")
	tg.wantExecutable("testdata/bin1/go-cmd-test"+exeSuffix, "go install go-cmd-test did not write to testdata/bin1/go-cmd-test")
}

// Issue 11065
func TestInstallToCurrentDirectoryCreatesExecutable(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	pkg := filepath.Join(tg.pwd(), "testdata", "src", "go-cmd-test")
	tg.creatingTemp(filepath.Join(pkg, "go-cmd-test"+exeSuffix))
	tg.setenv("GOBIN", pkg)
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.cd(pkg)
	tg.run("install")
	tg.wantExecutable("go-cmd-test"+exeSuffix, "go install did not write to current directory")
}

// Without $GOBIN set, installing a program outside $GOPATH should fail
// (there is nowhere to install it).
func TestInstallWithoutDestinationFails(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.runFail("install", "testdata/src/go-cmd-test/helloworld.go")
	tg.grepStderr("no install location for .go files listed on command line", "wrong error")
}

// With $GOBIN set, should install there.
func TestInstallToGOBINCommandLinePackage(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	gobin := filepath.Join(tg.pwd(), "testdata", "bin1")
	tg.creatingTemp(gobin)
	tg.setenv("GOBIN", gobin)
	tg.run("install", "testdata/src/go-cmd-test/helloworld.go")
	tg.wantExecutable("testdata/bin1/helloworld"+exeSuffix, "go install testdata/src/go-cmd-test/helloworld.go did not write testdata/bin1/helloworld")
}

func TestGoGetNonPkg(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.tempDir("gobin")
	tg.setenv("GOPATH", tg.path("."))
	tg.setenv("GOBIN", tg.path("gobin"))
	tg.runFail("get", "-d", "golang.org/x/tools")
	tg.grepStderr("golang.org/x/tools: no buildable Go source files", "missing error")
	tg.runFail("get", "-d", "-u", "golang.org/x/tools")
	tg.grepStderr("golang.org/x/tools: no buildable Go source files", "missing error")
	tg.runFail("get", "-d", "golang.org/x/tools")
	tg.grepStderr("golang.org/x/tools: no buildable Go source files", "missing error")
}

func TestGoGetTestOnlyPkg(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.tempDir("gopath")
	tg.setenv("GOPATH", tg.path("gopath"))
	tg.run("get", "golang.org/x/tour/content")
	tg.run("get", "-t", "golang.org/x/tour/content")
}

func TestInstalls(t *testing.T) {
	if testing.Short() {
		t.Skip("don't install into GOROOT in short mode")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("gobin")
	tg.setenv("GOPATH", tg.path("."))
	goroot := runtime.GOROOT()
	tg.setenv("GOROOT", goroot)

	// cmd/fix installs into tool
	tg.run("env", "GOOS")
	goos := strings.TrimSpace(tg.getStdout())
	tg.setenv("GOOS", goos)
	tg.run("env", "GOARCH")
	goarch := strings.TrimSpace(tg.getStdout())
	tg.setenv("GOARCH", goarch)
	fixbin := filepath.Join(goroot, "pkg", "tool", goos+"_"+goarch, "fix") + exeSuffix
	tg.must(os.RemoveAll(fixbin))
	tg.run("install", "cmd/fix")
	tg.wantExecutable(fixbin, "did not install cmd/fix to $GOROOT/pkg/tool")
	tg.must(os.Remove(fixbin))
	tg.setenv("GOBIN", tg.path("gobin"))
	tg.run("install", "cmd/fix")
	tg.wantExecutable(fixbin, "did not install cmd/fix to $GOROOT/pkg/tool with $GOBIN set")
	tg.unsetenv("GOBIN")

	// gopath program installs into GOBIN
	tg.tempFile("src/progname/p.go", `package main; func main() {}`)
	tg.setenv("GOBIN", tg.path("gobin"))
	tg.run("install", "progname")
	tg.unsetenv("GOBIN")
	tg.wantExecutable(tg.path("gobin/progname")+exeSuffix, "did not install progname to $GOBIN/progname")

	// gopath program installs into GOPATH/bin
	tg.run("install", "progname")
	tg.wantExecutable(tg.path("bin/progname")+exeSuffix, "did not install progname to $GOPATH/bin/progname")
}

func TestRejectRelativeDotPathInGOPATHCommandLinePackage(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", ".")
	tg.runFail("build", "testdata/src/go-cmd-test/helloworld.go")
	tg.grepStderr("GOPATH entry is relative", "expected an error message rejecting relative GOPATH entries")
}

func TestRejectRelativePathsInGOPATH(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	sep := string(filepath.ListSeparator)
	tg.setenv("GOPATH", sep+filepath.Join(tg.pwd(), "testdata")+sep+".")
	tg.runFail("build", "go-cmd-test")
	tg.grepStderr("GOPATH entry is relative", "expected an error message rejecting relative GOPATH entries")
}

func TestRejectRelativePathsInGOPATHCommandLinePackage(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", "testdata")
	tg.runFail("build", "testdata/src/go-cmd-test/helloworld.go")
	tg.grepStderr("GOPATH entry is relative", "expected an error message rejecting relative GOPATH entries")
}

// Issue 4104.
func TestGoTestWithPackageListedMultipleTimes(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.run("test", "errors", "errors", "errors", "errors", "errors")
	if strings.Contains(strings.TrimSpace(tg.getStdout()), "\n") {
		t.Error("go test errors errors errors errors errors tested the same package multiple times")
	}
}

func TestGoListHasAConsistentOrder(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.run("list", "std")
	first := tg.getStdout()
	tg.run("list", "std")
	if first != tg.getStdout() {
		t.Error("go list std ordering is inconsistent")
	}
}

func TestGoListStdDoesNotIncludeCommands(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.run("list", "std")
	tg.grepStdoutNot("cmd/", "go list std shows commands")
}

func TestGoListCmdOnlyShowsCommands(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.run("list", "cmd")
	out := strings.TrimSpace(tg.getStdout())
	for _, line := range strings.Split(out, "\n") {
		if !strings.Contains(line, "cmd/") {
			t.Error("go list cmd shows non-commands")
			break
		}
	}
}

func TestGoListDedupsPackages(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.run("list", "xtestonly", "./testdata/src/xtestonly/...")
	got := strings.TrimSpace(tg.getStdout())
	const want = "xtestonly"
	if got != want {
		t.Errorf("got %q; want %q", got, want)
	}
}

// Issue 4096. Validate the output of unsuccessful go install foo/quxx.
func TestUnsuccessfulGoInstallShouldMentionMissingPackage(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.runFail("install", "foo/quxx")
	if tg.grepCountBoth(`cannot find package "foo/quxx" in any of`) != 1 {
		t.Error(`go install foo/quxx expected error: .*cannot find package "foo/quxx" in any of`)
	}
}

func TestGOROOTSearchFailureReporting(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.runFail("install", "foo/quxx")
	if tg.grepCountBoth(regexp.QuoteMeta(filepath.Join("foo", "quxx"))+` \(from \$GOROOT\)$`) != 1 {
		t.Error(`go install foo/quxx expected error: .*foo/quxx (from $GOROOT)`)
	}
}

func TestMultipleGOPATHEntriesReportedSeparately(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	sep := string(filepath.ListSeparator)
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata", "a")+sep+filepath.Join(tg.pwd(), "testdata", "b"))
	tg.runFail("install", "foo/quxx")
	if tg.grepCountBoth(`testdata[/\\].[/\\]src[/\\]foo[/\\]quxx`) != 2 {
		t.Error(`go install foo/quxx expected error: .*testdata/a/src/foo/quxx (from $GOPATH)\n.*testdata/b/src/foo/quxx`)
	}
}

// Test (from $GOPATH) annotation is reported for the first GOPATH entry,
func TestMentionGOPATHInFirstGOPATHEntry(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	sep := string(filepath.ListSeparator)
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata", "a")+sep+filepath.Join(tg.pwd(), "testdata", "b"))
	tg.runFail("install", "foo/quxx")
	if tg.grepCountBoth(regexp.QuoteMeta(filepath.Join("testdata", "a", "src", "foo", "quxx"))+` \(from \$GOPATH\)$`) != 1 {
		t.Error(`go install foo/quxx expected error: .*testdata/a/src/foo/quxx (from $GOPATH)`)
	}
}

// but not on the second.
func TestMentionGOPATHNotOnSecondEntry(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	sep := string(filepath.ListSeparator)
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata", "a")+sep+filepath.Join(tg.pwd(), "testdata", "b"))
	tg.runFail("install", "foo/quxx")
	if tg.grepCountBoth(regexp.QuoteMeta(filepath.Join("testdata", "b", "src", "foo", "quxx"))+`$`) != 1 {
		t.Error(`go install foo/quxx expected error: .*testdata/b/src/foo/quxx`)
	}
}

func homeEnvName() string {
	switch runtime.GOOS {
	case "windows":
		return "USERPROFILE"
	case "plan9":
		return "home"
	default:
		return "HOME"
	}
}

func TestDefaultGOPATH(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("home/go")
	tg.setenv(homeEnvName(), tg.path("home"))

	tg.run("env", "GOPATH")
	tg.grepStdout(regexp.QuoteMeta(tg.path("home/go")), "want GOPATH=$HOME/go")

	tg.setenv("GOROOT", tg.path("home/go"))
	tg.run("env", "GOPATH")
	tg.grepStdoutNot(".", "want unset GOPATH because GOROOT=$HOME/go")

	tg.setenv("GOROOT", tg.path("home/go")+"/")
	tg.run("env", "GOPATH")
	tg.grepStdoutNot(".", "want unset GOPATH because GOROOT=$HOME/go/")
}

func TestDefaultGOPATHGet(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", "")
	tg.tempDir("home")
	tg.setenv(homeEnvName(), tg.path("home"))

	// warn for creating directory
	tg.run("get", "-v", "github.com/golang/example/hello")
	tg.grepStderr("created GOPATH="+regexp.QuoteMeta(tg.path("home/go"))+"; see 'go help gopath'", "did not create GOPATH")

	// no warning if directory already exists
	tg.must(os.RemoveAll(tg.path("home/go")))
	tg.tempDir("home/go")
	tg.run("get", "github.com/golang/example/hello")
	tg.grepStderrNot(".", "expected no output on standard error")

	// error if $HOME/go is a file
	tg.must(os.RemoveAll(tg.path("home/go")))
	tg.tempFile("home/go", "")
	tg.runFail("get", "github.com/golang/example/hello")
	tg.grepStderr(`mkdir .*[/\\]go: .*(not a directory|cannot find the path)`, "expected error because $HOME/go is a file")
}

func TestDefaultGOPATHPrintedSearchList(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", "")
	tg.tempDir("home")
	tg.setenv(homeEnvName(), tg.path("home"))

	tg.runFail("install", "github.com/golang/example/hello")
	tg.grepStderr(regexp.QuoteMeta(tg.path("home/go/src/github.com/golang/example/hello"))+`.*from \$GOPATH`, "expected default GOPATH")
}

// Issue 4186.  go get cannot be used to download packages to $GOROOT.
// Test that without GOPATH set, go get should fail.
func TestGoGetIntoGOROOT(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("src")

	// Fails because GOROOT=GOPATH
	tg.setenv("GOPATH", tg.path("."))
	tg.setenv("GOROOT", tg.path("."))
	tg.runFail("get", "-d", "github.com/golang/example/hello")
	tg.grepStderr("warning: GOPATH set to GOROOT", "go should detect GOPATH=GOROOT")
	tg.grepStderr(`\$GOPATH must not be set to \$GOROOT`, "go should detect GOPATH=GOROOT")

	// Fails because GOROOT=GOPATH after cleaning.
	tg.setenv("GOPATH", tg.path(".")+"/")
	tg.setenv("GOROOT", tg.path("."))
	tg.runFail("get", "-d", "github.com/golang/example/hello")
	tg.grepStderr("warning: GOPATH set to GOROOT", "go should detect GOPATH=GOROOT")
	tg.grepStderr(`\$GOPATH must not be set to \$GOROOT`, "go should detect GOPATH=GOROOT")

	tg.setenv("GOPATH", tg.path("."))
	tg.setenv("GOROOT", tg.path(".")+"/")
	tg.runFail("get", "-d", "github.com/golang/example/hello")
	tg.grepStderr("warning: GOPATH set to GOROOT", "go should detect GOPATH=GOROOT")
	tg.grepStderr(`\$GOPATH must not be set to \$GOROOT`, "go should detect GOPATH=GOROOT")

	// Fails because GOROOT=$HOME/go so default GOPATH unset.
	tg.tempDir("home/go")
	tg.setenv(homeEnvName(), tg.path("home"))
	tg.setenv("GOPATH", "")
	tg.setenv("GOROOT", tg.path("home/go"))
	tg.runFail("get", "-d", "github.com/golang/example/hello")
	tg.grepStderr(`\$GOPATH not set`, "expected GOPATH not set")

	tg.setenv(homeEnvName(), tg.path("home")+"/")
	tg.setenv("GOPATH", "")
	tg.setenv("GOROOT", tg.path("home/go"))
	tg.runFail("get", "-d", "github.com/golang/example/hello")
	tg.grepStderr(`\$GOPATH not set`, "expected GOPATH not set")

	tg.setenv(homeEnvName(), tg.path("home"))
	tg.setenv("GOPATH", "")
	tg.setenv("GOROOT", tg.path("home/go")+"/")
	tg.runFail("get", "-d", "github.com/golang/example/hello")
	tg.grepStderr(`\$GOPATH not set`, "expected GOPATH not set")
}

func TestLdflagsArgumentsWithSpacesIssue3941(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("main.go", `package main
		var extern string
		func main() {
			println(extern)
		}`)
	tg.run("run", "-ldflags", `-X "main.extern=hello world"`, tg.path("main.go"))
	tg.grepStderr("^hello world", `ldflags -X "main.extern=hello world"' failed`)
}

func TestGoTestCpuprofileLeavesBinaryBehind(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.makeTempdir()
	tg.cd(tg.path("."))
	tg.run("test", "-cpuprofile", "errors.prof", "errors")
	tg.wantExecutable("errors.test"+exeSuffix, "go test -cpuprofile did not create errors.test")
}

func TestGoTestCpuprofileDashOControlsBinaryLocation(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.makeTempdir()
	tg.cd(tg.path("."))
	tg.run("test", "-cpuprofile", "errors.prof", "-o", "myerrors.test"+exeSuffix, "errors")
	tg.wantExecutable("myerrors.test"+exeSuffix, "go test -cpuprofile -o myerrors.test did not create myerrors.test")
}

func TestGoTestMutexprofileLeavesBinaryBehind(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.makeTempdir()
	tg.cd(tg.path("."))
	tg.run("test", "-mutexprofile", "errors.prof", "errors")
	tg.wantExecutable("errors.test"+exeSuffix, "go test -mutexprofile did not create errors.test")
}

func TestGoTestMutexprofileDashOControlsBinaryLocation(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.makeTempdir()
	tg.cd(tg.path("."))
	tg.run("test", "-mutexprofile", "errors.prof", "-o", "myerrors.test"+exeSuffix, "errors")
	tg.wantExecutable("myerrors.test"+exeSuffix, "go test -mutexprofile -o myerrors.test did not create myerrors.test")
}

func TestGoTestDashCDashOControlsBinaryLocation(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.makeTempdir()
	tg.run("test", "-c", "-o", tg.path("myerrors.test"+exeSuffix), "errors")
	tg.wantExecutable(tg.path("myerrors.test"+exeSuffix), "go test -c -o myerrors.test did not create myerrors.test")
}

func TestGoTestDashOWritesBinary(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.makeTempdir()
	tg.run("test", "-o", tg.path("myerrors.test"+exeSuffix), "errors")
	tg.wantExecutable(tg.path("myerrors.test"+exeSuffix), "go test -o myerrors.test did not create myerrors.test")
}

func TestGoTestDashIDashOWritesBinary(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.makeTempdir()
	tg.run("test", "-v", "-i", "-o", tg.path("myerrors.test"+exeSuffix), "errors")
	tg.grepBothNot("PASS|FAIL", "test should not have run")
	tg.wantExecutable(tg.path("myerrors.test"+exeSuffix), "go test -o myerrors.test did not create myerrors.test")
}

// Issue 4568.
func TestSymlinksList(t *testing.T) {
	switch runtime.GOOS {
	case "plan9", "windows":
		t.Skipf("skipping symlink test on %s", runtime.GOOS)
	}

	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.tempDir("src")
	tg.must(os.Symlink(tg.path("."), tg.path("src/dir1")))
	tg.tempFile("src/dir1/p.go", "package p")
	tg.setenv("GOPATH", tg.path("."))
	tg.cd(tg.path("src"))
	tg.run("list", "-f", "{{.Root}}", "dir1")
	if strings.TrimSpace(tg.getStdout()) != tg.path(".") {
		t.Error("confused by symlinks")
	}
}

// Issue 14054.
func TestSymlinksVendor(t *testing.T) {
	switch runtime.GOOS {
	case "plan9", "windows":
		t.Skipf("skipping symlink test on %s", runtime.GOOS)
	}

	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.tempDir("gopath/src/dir1/vendor/v")
	tg.tempFile("gopath/src/dir1/p.go", "package main\nimport _ `v`\nfunc main(){}")
	tg.tempFile("gopath/src/dir1/vendor/v/v.go", "package v")
	tg.must(os.Symlink(tg.path("gopath/src/dir1"), tg.path("symdir1")))
	tg.setenv("GOPATH", tg.path("gopath"))
	tg.cd(tg.path("symdir1"))
	tg.run("list", "-f", "{{.Root}}", ".")
	if strings.TrimSpace(tg.getStdout()) != tg.path("gopath") {
		t.Error("list confused by symlinks")
	}

	// All of these should succeed, not die in vendor-handling code.
	tg.run("run", "p.go")
	tg.run("build")
	tg.run("install")
}

// Issue 15201.
func TestSymlinksVendor15201(t *testing.T) {
	switch runtime.GOOS {
	case "plan9", "windows":
		t.Skipf("skipping symlink test on %s", runtime.GOOS)
	}

	tg := testgo(t)
	defer tg.cleanup()

	tg.tempDir("gopath/src/x/y/_vendor/src/x")
	tg.must(os.Symlink("../../..", tg.path("gopath/src/x/y/_vendor/src/x/y")))
	tg.tempFile("gopath/src/x/y/w/w.go", "package w\nimport \"x/y/z\"\n")
	tg.must(os.Symlink("../_vendor/src", tg.path("gopath/src/x/y/w/vendor")))
	tg.tempFile("gopath/src/x/y/z/z.go", "package z\n")

	tg.setenv("GOPATH", tg.path("gopath/src/x/y/_vendor")+string(filepath.ListSeparator)+tg.path("gopath"))
	tg.cd(tg.path("gopath/src"))
	tg.run("list", "./...")
}

func TestSymlinksInternal(t *testing.T) {
	switch runtime.GOOS {
	case "plan9", "windows":
		t.Skipf("skipping symlink test on %s", runtime.GOOS)
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.tempDir("gopath/src/dir1/internal/v")
	tg.tempFile("gopath/src/dir1/p.go", "package main\nimport _ `dir1/internal/v`\nfunc main(){}")
	tg.tempFile("gopath/src/dir1/internal/v/v.go", "package v")
	tg.must(os.Symlink(tg.path("gopath/src/dir1"), tg.path("symdir1")))
	tg.setenv("GOPATH", tg.path("gopath"))
	tg.cd(tg.path("symdir1"))
	tg.run("list", "-f", "{{.Root}}", ".")
	if strings.TrimSpace(tg.getStdout()) != tg.path("gopath") {
		t.Error("list confused by symlinks")
	}

	// All of these should succeed, not die in internal-handling code.
	tg.run("run", "p.go")
	tg.run("build")
	tg.run("install")
}

// Issue 4515.
func TestInstallWithTags(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("bin")
	tg.tempFile("src/example/a/main.go", `package main
		func main() {}`)
	tg.tempFile("src/example/b/main.go", `// +build mytag

		package main
		func main() {}`)
	tg.setenv("GOPATH", tg.path("."))
	tg.run("install", "-tags", "mytag", "example/a", "example/b")
	tg.wantExecutable(tg.path("bin/a"+exeSuffix), "go install example/a example/b did not install binaries")
	tg.wantExecutable(tg.path("bin/b"+exeSuffix), "go install example/a example/b did not install binaries")
	tg.must(os.Remove(tg.path("bin/a" + exeSuffix)))
	tg.must(os.Remove(tg.path("bin/b" + exeSuffix)))
	tg.run("install", "-tags", "mytag", "example/...")
	tg.wantExecutable(tg.path("bin/a"+exeSuffix), "go install example/... did not install binaries")
	tg.wantExecutable(tg.path("bin/b"+exeSuffix), "go install example/... did not install binaries")
	tg.run("list", "-tags", "mytag", "example/b...")
	if strings.TrimSpace(tg.getStdout()) != "example/b" {
		t.Error("go list example/b did not find example/b")
	}
}

// Issue 4773
func TestCaseCollisions(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("src/example/a/pkg")
	tg.tempDir("src/example/a/Pkg")
	tg.tempDir("src/example/b")
	tg.setenv("GOPATH", tg.path("."))
	tg.tempFile("src/example/a/a.go", `package p
		import (
			_ "example/a/pkg"
			_ "example/a/Pkg"
		)`)
	tg.tempFile("src/example/a/pkg/pkg.go", `package pkg`)
	tg.tempFile("src/example/a/Pkg/pkg.go", `package pkg`)
	tg.runFail("list", "example/a")
	tg.grepStderr("case-insensitive import collision", "go list example/a did not report import collision")
	tg.tempFile("src/example/b/file.go", `package b`)
	tg.tempFile("src/example/b/FILE.go", `package b`)
	f, err := os.Open(tg.path("src/example/b"))
	tg.must(err)
	names, err := f.Readdirnames(0)
	tg.must(err)
	tg.check(f.Close())
	args := []string{"list"}
	if len(names) == 2 {
		// case-sensitive file system, let directory read find both files
		args = append(args, "example/b")
	} else {
		// case-insensitive file system, list files explicitly on command line
		args = append(args, tg.path("src/example/b/file.go"), tg.path("src/example/b/FILE.go"))
	}
	tg.runFail(args...)
	tg.grepStderr("case-insensitive file name collision", "go list example/b did not report file name collision")
}

// Issue 8181.
func TestGoGetDashTIssue8181(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))
	tg.run("get", "-v", "-t", "github.com/rsc/go-get-issue-8181/a", "github.com/rsc/go-get-issue-8181/b")
	tg.run("list", "...")
	tg.grepStdout("x/build/gerrit", "missing expected x/build/gerrit")
}

func TestIssue11307(t *testing.T) {
	// go get -u was not working except in checkout directory
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))
	tg.run("get", "github.com/rsc/go-get-issue-11307")
	tg.run("get", "-u", "github.com/rsc/go-get-issue-11307") // was failing
}

func TestShadowingLogic(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	pwd := tg.pwd()
	sep := string(filepath.ListSeparator)
	tg.setenv("GOPATH", filepath.Join(pwd, "testdata", "shadow", "root1")+sep+filepath.Join(pwd, "testdata", "shadow", "root2"))

	// The math in root1 is not "math" because the standard math is.
	tg.run("list", "-f", "({{.ImportPath}}) ({{.ConflictDir}})", "./testdata/shadow/root1/src/math")
	pwdForwardSlash := strings.Replace(pwd, string(os.PathSeparator), "/", -1)
	if !strings.HasPrefix(pwdForwardSlash, "/") {
		pwdForwardSlash = "/" + pwdForwardSlash
	}
	// The output will have makeImportValid applies, but we only
	// bother to deal with characters we might reasonably see.
	for _, r := range " :" {
		pwdForwardSlash = strings.Replace(pwdForwardSlash, string(r), "_", -1)
	}
	want := "(_" + pwdForwardSlash + "/testdata/shadow/root1/src/math) (" + filepath.Join(runtime.GOROOT(), "src", "math") + ")"
	if strings.TrimSpace(tg.getStdout()) != want {
		t.Error("shadowed math is not shadowed; looking for", want)
	}

	// The foo in root1 is "foo".
	tg.run("list", "-f", "({{.ImportPath}}) ({{.ConflictDir}})", "./testdata/shadow/root1/src/foo")
	if strings.TrimSpace(tg.getStdout()) != "(foo) ()" {
		t.Error("unshadowed foo is shadowed")
	}

	// The foo in root2 is not "foo" because the foo in root1 got there first.
	tg.run("list", "-f", "({{.ImportPath}}) ({{.ConflictDir}})", "./testdata/shadow/root2/src/foo")
	want = "(_" + pwdForwardSlash + "/testdata/shadow/root2/src/foo) (" + filepath.Join(pwd, "testdata", "shadow", "root1", "src", "foo") + ")"
	if strings.TrimSpace(tg.getStdout()) != want {
		t.Error("shadowed foo is not shadowed; looking for", want)
	}

	// The error for go install should mention the conflicting directory.
	tg.runFail("install", "./testdata/shadow/root2/src/foo")
	want = "go install: no install location for " + filepath.Join(pwd, "testdata", "shadow", "root2", "src", "foo") + ": hidden by " + filepath.Join(pwd, "testdata", "shadow", "root1", "src", "foo")
	if strings.TrimSpace(tg.getStderr()) != want {
		t.Error("wrong shadowed install error; looking for", want)
	}
}

// Only succeeds if source order is preserved.
func TestSourceFileNameOrderPreserved(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "testdata/example1_test.go", "testdata/example2_test.go")
}

// Check that coverage analysis works at all.
// Don't worry about the exact numbers but require not 0.0%.
func checkCoverage(tg *testgoData, data string) {
	if regexp.MustCompile(`[^0-9]0\.0%`).MatchString(data) {
		tg.t.Error("some coverage results are 0.0%")
	}
	tg.t.Log(data)
}

func TestCoverageRuns(t *testing.T) {
	if testing.Short() {
		t.Skip("don't build libraries for coverage in short mode")
	}
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "-short", "-coverpkg=strings", "strings", "regexp")
	data := tg.getStdout() + tg.getStderr()
	tg.run("test", "-short", "-cover", "strings", "math", "regexp")
	data += tg.getStdout() + tg.getStderr()
	checkCoverage(tg, data)
}

// Check that coverage analysis uses set mode.
func TestCoverageUsesSetMode(t *testing.T) {
	if testing.Short() {
		t.Skip("don't build libraries for coverage in short mode")
	}
	tg := testgo(t)
	defer tg.cleanup()
	tg.creatingTemp("testdata/cover.out")
	tg.run("test", "-short", "-cover", "encoding/binary", "-coverprofile=testdata/cover.out")
	data := tg.getStdout() + tg.getStderr()
	if out, err := ioutil.ReadFile("testdata/cover.out"); err != nil {
		t.Error(err)
	} else {
		if !bytes.Contains(out, []byte("mode: set")) {
			t.Error("missing mode: set")
		}
	}
	checkCoverage(tg, data)
}

func TestCoverageUsesAtomicModeForRace(t *testing.T) {
	if testing.Short() {
		t.Skip("don't build libraries for coverage in short mode")
	}
	if !canRace {
		t.Skip("skipping because race detector not supported")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.creatingTemp("testdata/cover.out")
	tg.run("test", "-short", "-race", "-cover", "encoding/binary", "-coverprofile=testdata/cover.out")
	data := tg.getStdout() + tg.getStderr()
	if out, err := ioutil.ReadFile("testdata/cover.out"); err != nil {
		t.Error(err)
	} else {
		if !bytes.Contains(out, []byte("mode: atomic")) {
			t.Error("missing mode: atomic")
		}
	}
	checkCoverage(tg, data)
}

func TestCoverageUsesActualSettingToOverrideEvenForRace(t *testing.T) {
	if testing.Short() {
		t.Skip("don't build libraries for coverage in short mode")
	}
	if !canRace {
		t.Skip("skipping because race detector not supported")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.creatingTemp("testdata/cover.out")
	tg.run("test", "-short", "-race", "-cover", "encoding/binary", "-covermode=count", "-coverprofile=testdata/cover.out")
	data := tg.getStdout() + tg.getStderr()
	if out, err := ioutil.ReadFile("testdata/cover.out"); err != nil {
		t.Error(err)
	} else {
		if !bytes.Contains(out, []byte("mode: count")) {
			t.Error("missing mode: count")
		}
	}
	checkCoverage(tg, data)
}

func TestCoverageImportMainLoop(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("test", "importmain/test")
	tg.grepStderr("not an importable package", "did not detect import main")
	tg.runFail("test", "-cover", "importmain/test")
	tg.grepStderr("not an importable package", "did not detect import main")
}

func TestTestEmpty(t *testing.T) {
	if !canRace {
		t.Skip("no race detector")
	}

	wd, _ := os.Getwd()
	testdata := filepath.Join(wd, "testdata")

	for _, dir := range []string{"pkg", "test", "xtest", "pkgtest", "pkgxtest", "pkgtestxtest", "testxtest"} {
		t.Run(dir, func(t *testing.T) {
			tg := testgo(t)
			defer tg.cleanup()
			tg.setenv("GOPATH", testdata)
			tg.cd(filepath.Join(testdata, "src/empty/"+dir))
			tg.run("test", "-cover", "-coverpkg=.", "-race")
		})
		if testing.Short() {
			break
		}
	}
}

func TestTestRaceInstall(t *testing.T) {
	if !canRace {
		t.Skip("no race detector")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))

	tg.tempDir("pkg")
	pkgdir := tg.path("pkg")
	tg.run("install", "-race", "-pkgdir="+pkgdir, "std")
	tg.run("test", "-race", "-pkgdir="+pkgdir, "-i", "-v", "empty/pkg")
	if tg.getStderr() != "" {
		t.Error("go test -i -race: rebuilds cached packages")
	}
}

func TestBuildDryRunWithCgo(t *testing.T) {
	if !canCgo {
		t.Skip("skipping because cgo not enabled")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.tempFile("foo.go", `package main

/*
#include <limits.h>
*/
import "C"

func main() {
        println(C.INT_MAX)
}`)
	tg.run("build", "-n", tg.path("foo.go"))
	tg.grepStderrNot(`os.Stat .* no such file or directory`, "unexpected stat of archive file")
}

func TestCoverageWithCgo(t *testing.T) {
	if !canCgo {
		t.Skip("skipping because cgo not enabled")
	}

	for _, dir := range []string{"cgocover", "cgocover2", "cgocover3", "cgocover4"} {
		t.Run(dir, func(t *testing.T) {
			tg := testgo(t)
			tg.parallel()
			defer tg.cleanup()
			tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
			tg.run("test", "-short", "-cover", dir)
			data := tg.getStdout() + tg.getStderr()
			checkCoverage(tg, data)
		})
	}
}

func TestCgoDependsOnSyscall(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test that removes $GOROOT/pkg/*_race in short mode")
	}
	if !canCgo {
		t.Skip("skipping because cgo not enabled")
	}
	if !canRace {
		t.Skip("skipping because race detector not supported")
	}

	tg := testgo(t)
	defer tg.cleanup()
	files, err := filepath.Glob(filepath.Join(runtime.GOROOT(), "pkg", "*_race"))
	tg.must(err)
	for _, file := range files {
		tg.check(os.RemoveAll(file))
	}
	tg.tempFile("src/foo/foo.go", `
		package foo
		//#include <stdio.h>
		import "C"`)
	tg.setenv("GOPATH", tg.path("."))
	tg.run("build", "-race", "foo")
}

func TestCgoShowsFullPathNames(t *testing.T) {
	if !canCgo {
		t.Skip("skipping because cgo not enabled")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("src/x/y/dirname/foo.go", `
		package foo
		import "C"
		func f() {`)
	tg.setenv("GOPATH", tg.path("."))
	tg.runFail("build", "x/y/dirname")
	tg.grepBoth("x/y/dirname", "error did not use full path")
}

func TestCgoHandlesWlORIGIN(t *testing.T) {
	if !canCgo {
		t.Skip("skipping because cgo not enabled")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("src/origin/origin.go", `package origin
		// #cgo !darwin LDFLAGS: -Wl,-rpath,$ORIGIN
		// void f(void) {}
		import "C"
		func f() { C.f() }`)
	tg.setenv("GOPATH", tg.path("."))
	tg.run("build", "origin")
}

func TestCgoPkgConfig(t *testing.T) {
	if !canCgo {
		t.Skip("skipping because cgo not enabled")
	}
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()

	tg.run("env", "PKG_CONFIG")
	pkgConfig := strings.TrimSpace(tg.getStdout())
	if out, err := exec.Command(pkgConfig, "--atleast-pkgconfig-version", "0.24").CombinedOutput(); err != nil {
		t.Skipf("%s --atleast-pkgconfig-version 0.24: %v\n%s", pkgConfig, err, out)
	}

	// OpenBSD's pkg-config is strict about whitespace and only
	// supports backslash-escaped whitespace. It does not support
	// quotes, which the normal freedesktop.org pkg-config does
	// support. See http://man.openbsd.org/pkg-config.1
	tg.tempFile("foo.pc", `
Name: foo
Description: The foo library
Version: 1.0.0
Cflags: -Dhello=10 -Dworld=+32 -DDEFINED_FROM_PKG_CONFIG=hello\ world
`)
	tg.tempFile("foo.go", `package main

/*
#cgo pkg-config: foo
int value() {
	return DEFINED_FROM_PKG_CONFIG;
}
*/
import "C"
import "os"

func main() {
	if C.value() != 42 {
		println("value() =", C.value(), "wanted 42")
		os.Exit(1)
	}
}
`)
	tg.setenv("PKG_CONFIG_PATH", tg.path("."))
	tg.run("run", tg.path("foo.go"))
}

// "go test -c -test.bench=XXX errors" should not hang
func TestIssue6480(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.makeTempdir()
	tg.cd(tg.path("."))
	tg.run("test", "-c", "-test.bench=XXX", "errors")
}

// cmd/cgo: undefined reference when linking a C-library using gccgo
func TestIssue7573(t *testing.T) {
	if !canCgo {
		t.Skip("skipping because cgo not enabled")
	}
	if _, err := exec.LookPath("gccgo"); err != nil {
		t.Skip("skipping because no gccgo compiler found")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("src/cgoref/cgoref.go", `
package main
// #cgo LDFLAGS: -L alibpath -lalib
// void f(void) {}
import "C"

func main() { C.f() }`)
	tg.setenv("GOPATH", tg.path("."))
	tg.run("build", "-n", "-compiler", "gccgo", "cgoref")
	tg.grepStderr(`gccgo.*\-L alibpath \-lalib`, `no Go-inline "#cgo LDFLAGS:" ("-L alibpath -lalib") passed to gccgo linking stage`)
}

func TestListTemplateContextFunction(t *testing.T) {
	t.Parallel()
	for _, tt := range []struct {
		v    string
		want string
	}{
		{"GOARCH", runtime.GOARCH},
		{"GOOS", runtime.GOOS},
		{"GOROOT", filepath.Clean(runtime.GOROOT())},
		{"GOPATH", os.Getenv("GOPATH")},
		{"CgoEnabled", ""},
		{"UseAllFiles", ""},
		{"Compiler", ""},
		{"BuildTags", ""},
		{"ReleaseTags", ""},
		{"InstallSuffix", ""},
	} {
		tt := tt
		t.Run(tt.v, func(t *testing.T) {
			tg := testgo(t)
			tg.parallel()
			defer tg.cleanup()
			tmpl := "{{context." + tt.v + "}}"
			tg.run("list", "-f", tmpl)
			if tt.want == "" {
				return
			}
			if got := strings.TrimSpace(tg.getStdout()); got != tt.want {
				t.Errorf("go list -f %q: got %q; want %q", tmpl, got, tt.want)
			}
		})
	}
}

// cmd/go: "go test" should fail if package does not build
func TestIssue7108(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("test", "notest")
}

// cmd/go: go test -a foo does not rebuild regexp.
func TestIssue6844(t *testing.T) {
	if testing.Short() {
		t.Skip("don't rebuild the standard library in short mode")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.creatingTemp("deps.test" + exeSuffix)
	tg.run("test", "-x", "-a", "-c", "testdata/dep_test.go")
	tg.grepStderr("regexp", "go test -x -a -c testdata/dep-test.go did not rebuild regexp")
}

func TestBuildDashIInstallsDependencies(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("src/x/y/foo/foo.go", `package foo
		func F() {}`)
	tg.tempFile("src/x/y/bar/bar.go", `package bar
		import "x/y/foo"
		func F() { foo.F() }`)
	tg.setenv("GOPATH", tg.path("."))

	checkbar := func(desc string) {
		tg.sleep()
		tg.must(os.Chtimes(tg.path("src/x/y/foo/foo.go"), time.Now(), time.Now()))
		tg.sleep()
		tg.run("build", "-v", "-i", "x/y/bar")
		tg.grepBoth("x/y/foo", "first build -i "+desc+" did not build x/y/foo")
		tg.run("build", "-v", "-i", "x/y/bar")
		tg.grepBothNot("x/y/foo", "second build -i "+desc+" built x/y/foo")
	}
	checkbar("pkg")
	tg.creatingTemp("bar" + exeSuffix)
	tg.tempFile("src/x/y/bar/bar.go", `package main
		import "x/y/foo"
		func main() { foo.F() }`)
	checkbar("cmd")
}

func TestGoBuildInTestOnlyDirectoryFailsWithAGoodError(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.runFail("build", "./testdata/testonly")
	tg.grepStderr("no buildable Go", "go build ./testdata/testonly produced unexpected error")
}

func TestGoTestDetectsTestOnlyImportCycles(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("test", "-c", "testcycle/p3")
	tg.grepStderr("import cycle not allowed in test", "go test testcycle/p3 produced unexpected error")

	tg.runFail("test", "-c", "testcycle/q1")
	tg.grepStderr("import cycle not allowed in test", "go test testcycle/q1 produced unexpected error")
}

func TestGoTestFooTestWorks(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "testdata/standalone_test.go")
}

func TestGoTestFlagsAfterPackage(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "testdata/flag_test.go", "-v", "-args", "-v=7") // Two distinct -v flags.
	tg.run("test", "-v", "testdata/flag_test.go", "-args", "-v=7") // Two distinct -v flags.
}

func TestGoTestXtestonlyWorks(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.run("clean", "-i", "xtestonly")
	tg.run("test", "xtestonly")
}

func TestGoTestBuildsAnXtestContainingOnlyNonRunnableExamples(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "-v", "./testdata/norunexample")
	tg.grepStdout("File with non-runnable example was built.", "file with non-runnable example was not built")
}

func TestGoGenerateHandlesSimpleCommand(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("skipping because windows has no echo command")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.run("generate", "./testdata/generate/test1.go")
	tg.grepStdout("Success", "go generate ./testdata/generate/test1.go generated wrong output")
}

func TestGoGenerateHandlesCommandAlias(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("skipping because windows has no echo command")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.run("generate", "./testdata/generate/test2.go")
	tg.grepStdout("Now is the time for all good men", "go generate ./testdata/generate/test2.go generated wrong output")
}

func TestGoGenerateVariableSubstitution(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("skipping because windows has no echo command")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.run("generate", "./testdata/generate/test3.go")
	tg.grepStdout(runtime.GOARCH+" test3.go:7 pabc xyzp/test3.go/123", "go generate ./testdata/generate/test3.go generated wrong output")
}

func TestGoGenerateRunFlag(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("skipping because windows has no echo command")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.run("generate", "-run", "y.s", "./testdata/generate/test4.go")
	tg.grepStdout("yes", "go generate -run yes ./testdata/generate/test4.go did not select yes")
	tg.grepStdoutNot("no", "go generate -run yes ./testdata/generate/test4.go selected no")
}

func TestGoGenerateEnv(t *testing.T) {
	switch runtime.GOOS {
	case "plan9", "windows":
		t.Skipf("skipping because %s does not have the env command", runtime.GOOS)
	}
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempFile("env.go", "package main\n\n//go:generate env")
	tg.run("generate", tg.path("env.go"))
	for _, v := range []string{"GOARCH", "GOOS", "GOFILE", "GOLINE", "GOPACKAGE", "DOLLAR"} {
		tg.grepStdout("^"+v+"=", "go generate environment missing "+v)
	}
}

func TestGoGenerateBadImports(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("skipping because windows has no echo command")
	}

	// This package has an invalid import causing an import cycle,
	// but go generate is supposed to still run.
	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.run("generate", "gencycle")
	tg.grepStdout("hello world", "go generate gencycle did not run generator")
}

func TestGoGetCustomDomainWildcard(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))
	tg.run("get", "-u", "rsc.io/pdf/...")
	tg.wantExecutable(tg.path("bin/pdfpasswd"+exeSuffix), "did not build rsc/io/pdf/pdfpasswd")
}

func TestGoGetInternalWildcard(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))
	// used to fail with errors about internal packages
	tg.run("get", "github.com/rsc/go-get-issue-11960/...")
}

func TestGoVetWithExternalTests(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.run("install", "cmd/vet")
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("vet", "vetpkg")
	tg.grepBoth("missing argument for Printf", "go vet vetpkg did not find missing argument for Printf")
}

func TestGoVetWithTags(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.run("install", "cmd/vet")
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("vet", "-tags", "tagtest", "vetpkg")
	tg.grepBoth(`c\.go.*wrong number of args for format`, "go get vetpkg did not run scan tagged file")
}

// Issue 9767.
func TestGoGetRscIoToolstash(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.tempDir("src/rsc.io")
	tg.setenv("GOPATH", tg.path("."))
	tg.cd(tg.path("src/rsc.io"))
	tg.run("get", "./toolstash")
}

// Issue 13037: Was not parsing <meta> tags in 404 served over HTTPS
func TestGoGetHTTPS404(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	switch runtime.GOOS {
	case "darwin", "linux", "freebsd":
	default:
		t.Skipf("test case does not work on %s", runtime.GOOS)
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.tempDir("src")
	tg.setenv("GOPATH", tg.path("."))
	tg.run("get", "bazil.org/fuse/fs/fstestutil")
}

// Test that you cannot import a main package.
// See golang.org/issue/4210 and golang.org/issue/17475.
func TestImportMain(t *testing.T) {
	tg := testgo(t)
	tg.parallel()
	defer tg.cleanup()

	// Importing package main from that package main's test should work.
	tg.tempFile("src/x/main.go", `package main
		var X int
		func main() {}`)
	tg.tempFile("src/x/main_test.go", `package main_test
		import xmain "x"
		import "testing"
		var _ = xmain.X
		func TestFoo(t *testing.T) {}
	`)
	tg.setenv("GOPATH", tg.path("."))
	tg.creatingTemp("x" + exeSuffix)
	tg.run("build", "x")
	tg.run("test", "x")

	// Importing package main from another package should fail.
	tg.tempFile("src/p1/p.go", `package p1
		import xmain "x"
		var _ = xmain.X
	`)
	tg.runFail("build", "p1")
	tg.grepStderr("import \"x\" is a program, not an importable package", "did not diagnose package main")

	// ... even in that package's test.
	tg.tempFile("src/p2/p.go", `package p2
	`)
	tg.tempFile("src/p2/p_test.go", `package p2
		import xmain "x"
		import "testing"
		var _ = xmain.X
		func TestFoo(t *testing.T) {}
	`)
	tg.run("build", "p2")
	tg.runFail("test", "p2")
	tg.grepStderr("import \"x\" is a program, not an importable package", "did not diagnose package main")

	// ... even if that package's test is an xtest.
	tg.tempFile("src/p3/p.go", `package p
	`)
	tg.tempFile("src/p3/p_test.go", `package p_test
		import xmain "x"
		import "testing"
		var _ = xmain.X
		func TestFoo(t *testing.T) {}
	`)
	tg.run("build", "p3")
	tg.runFail("test", "p3")
	tg.grepStderr("import \"x\" is a program, not an importable package", "did not diagnose package main")

	// ... even if that package is a package main
	tg.tempFile("src/p4/p.go", `package main
	func main() {}
	`)
	tg.tempFile("src/p4/p_test.go", `package main
		import xmain "x"
		import "testing"
		var _ = xmain.X
		func TestFoo(t *testing.T) {}
	`)
	tg.creatingTemp("p4" + exeSuffix)
	tg.run("build", "p4")
	tg.runFail("test", "p4")
	tg.grepStderr("import \"x\" is a program, not an importable package", "did not diagnose package main")

	// ... even if that package is a package main using an xtest.
	tg.tempFile("src/p5/p.go", `package main
	func main() {}
	`)
	tg.tempFile("src/p5/p_test.go", `package main_test
		import xmain "x"
		import "testing"
		var _ = xmain.X
		func TestFoo(t *testing.T) {}
	`)
	tg.creatingTemp("p5" + exeSuffix)
	tg.run("build", "p5")
	tg.runFail("test", "p5")
	tg.grepStderr("import \"x\" is a program, not an importable package", "did not diagnose package main")
}

// Test that you cannot use a local import in a package
// accessed by a non-local import (found in a GOPATH/GOROOT).
// See golang.org/issue/17475.
func TestImportLocal(t *testing.T) {
	tg := testgo(t)
	tg.parallel()
	defer tg.cleanup()

	tg.tempFile("src/dir/x/x.go", `package x
		var X int
	`)
	tg.setenv("GOPATH", tg.path("."))
	tg.run("build", "dir/x")

	// Ordinary import should work.
	tg.tempFile("src/dir/p0/p.go", `package p0
		import "dir/x"
		var _ = x.X
	`)
	tg.run("build", "dir/p0")

	// Relative import should not.
	tg.tempFile("src/dir/p1/p.go", `package p1
		import "../x"
		var _ = x.X
	`)
	tg.runFail("build", "dir/p1")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// ... even in a test.
	tg.tempFile("src/dir/p2/p.go", `package p2
	`)
	tg.tempFile("src/dir/p2/p_test.go", `package p2
		import "../x"
		import "testing"
		var _ = x.X
		func TestFoo(t *testing.T) {}
	`)
	tg.run("build", "dir/p2")
	tg.runFail("test", "dir/p2")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// ... even in an xtest.
	tg.tempFile("src/dir/p2/p_test.go", `package p2_test
		import "../x"
		import "testing"
		var _ = x.X
		func TestFoo(t *testing.T) {}
	`)
	tg.run("build", "dir/p2")
	tg.runFail("test", "dir/p2")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// Relative import starting with ./ should not work either.
	tg.tempFile("src/dir/d.go", `package dir
		import "./x"
		var _ = x.X
	`)
	tg.runFail("build", "dir")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// ... even in a test.
	tg.tempFile("src/dir/d.go", `package dir
	`)
	tg.tempFile("src/dir/d_test.go", `package dir
		import "./x"
		import "testing"
		var _ = x.X
		func TestFoo(t *testing.T) {}
	`)
	tg.run("build", "dir")
	tg.runFail("test", "dir")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// ... even in an xtest.
	tg.tempFile("src/dir/d_test.go", `package dir_test
		import "./x"
		import "testing"
		var _ = x.X
		func TestFoo(t *testing.T) {}
	`)
	tg.run("build", "dir")
	tg.runFail("test", "dir")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// Relative import plain ".." should not work.
	tg.tempFile("src/dir/x/y/y.go", `package dir
		import ".."
		var _ = x.X
	`)
	tg.runFail("build", "dir/x/y")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// ... even in a test.
	tg.tempFile("src/dir/x/y/y.go", `package y
	`)
	tg.tempFile("src/dir/x/y/y_test.go", `package y
		import ".."
		import "testing"
		var _ = x.X
		func TestFoo(t *testing.T) {}
	`)
	tg.run("build", "dir/x/y")
	tg.runFail("test", "dir/x/y")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// ... even in an x test.
	tg.tempFile("src/dir/x/y/y_test.go", `package y_test
		import ".."
		import "testing"
		var _ = x.X
		func TestFoo(t *testing.T) {}
	`)
	tg.run("build", "dir/x/y")
	tg.runFail("test", "dir/x/y")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// Relative import "." should not work.
	tg.tempFile("src/dir/x/xx.go", `package x
		import "."
		var _ = x.X
	`)
	tg.runFail("build", "dir/x")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// ... even in a test.
	tg.tempFile("src/dir/x/xx.go", `package x
	`)
	tg.tempFile("src/dir/x/xx_test.go", `package x
		import "."
		import "testing"
		var _ = x.X
		func TestFoo(t *testing.T) {}
	`)
	tg.run("build", "dir/x")
	tg.runFail("test", "dir/x")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")

	// ... even in an xtest.
	tg.tempFile("src/dir/x/xx.go", `package x
	`)
	tg.tempFile("src/dir/x/xx_test.go", `package x_test
		import "."
		import "testing"
		var _ = x.X
		func TestFoo(t *testing.T) {}
	`)
	tg.run("build", "dir/x")
	tg.runFail("test", "dir/x")
	tg.grepStderr("local import.*in non-local package", "did not diagnose local import")
}

func TestGoGetInsecure(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))
	tg.failSSH()

	const repo = "insecure.go-get-issue-15410.appspot.com/pkg/p"

	// Try go get -d of HTTP-only repo (should fail).
	tg.runFail("get", "-d", repo)

	// Try again with -insecure (should succeed).
	tg.run("get", "-d", "-insecure", repo)

	// Try updating without -insecure (should fail).
	tg.runFail("get", "-d", "-u", "-f", repo)
}

func TestGoGetUpdateInsecure(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))

	const repo = "github.com/golang/example"

	// Clone the repo via HTTP manually.
	cmd := exec.Command("git", "clone", "-q", "http://"+repo, tg.path("src/"+repo))
	if out, err := cmd.CombinedOutput(); err != nil {
		t.Fatalf("cloning %v repo: %v\n%s", repo, err, out)
	}

	// Update without -insecure should fail.
	// Update with -insecure should succeed.
	// We need -f to ignore import comments.
	const pkg = repo + "/hello"
	tg.runFail("get", "-d", "-u", "-f", pkg)
	tg.run("get", "-d", "-u", "-f", "-insecure", pkg)
}

func TestGoGetInsecureCustomDomain(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))

	const repo = "insecure.go-get-issue-15410.appspot.com/pkg/p"
	tg.runFail("get", "-d", repo)
	tg.run("get", "-d", "-insecure", repo)
}

func TestGoRunDirs(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.cd("testdata/rundir")
	tg.runFail("run", "x.go", "sub/sub.go")
	tg.grepStderr("named files must all be in one directory; have ./ and sub/", "wrong output")
	tg.runFail("run", "sub/sub.go", "x.go")
	tg.grepStderr("named files must all be in one directory; have sub/ and ./", "wrong output")
}

func TestGoInstallPkgdir(t *testing.T) {
	tg := testgo(t)
	tg.parallel()
	defer tg.cleanup()
	tg.makeTempdir()
	pkg := tg.path(".")
	tg.run("install", "-pkgdir", pkg, "errors")
	_, err := os.Stat(filepath.Join(pkg, "errors.a"))
	tg.must(err)
	_, err = os.Stat(filepath.Join(pkg, "runtime.a"))
	tg.must(err)
}

func TestGoTestRaceInstallCgo(t *testing.T) {
	switch sys := runtime.GOOS + "/" + runtime.GOARCH; sys {
	case "darwin/amd64", "freebsd/amd64", "linux/amd64", "windows/amd64":
		// ok
	default:
		t.Skip("no race detector on %s", sys)
	}

	if !build.Default.CgoEnabled {
		t.Skip("no race detector without cgo")
	}

	// golang.org/issue/10500.
	// This used to install a race-enabled cgo.
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("tool", "-n", "cgo")
	cgo := strings.TrimSpace(tg.stdout.String())
	old, err := os.Stat(cgo)
	tg.must(err)
	tg.run("test", "-race", "-i", "runtime/race")
	new, err := os.Stat(cgo)
	tg.must(err)
	if new.ModTime() != old.ModTime() {
		t.Fatalf("go test -i runtime/race reinstalled cmd/cgo")
	}
}

func TestGoTestRaceFailures(t *testing.T) {
	if !canRace {
		t.Skip("skipping because race detector not supported")
	}

	tg := testgo(t)
	tg.parallel()
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))

	tg.run("test", "testrace")

	tg.runFail("test", "-race", "testrace")
	tg.grepStdout("FAIL: TestRace", "TestRace did not fail")
	tg.grepBothNot("PASS", "something passed")

	tg.runFail("test", "-race", "testrace", "-run", "XXX", "-bench", ".")
	tg.grepStdout("FAIL: BenchmarkRace", "BenchmarkRace did not fail")
	tg.grepBothNot("PASS", "something passed")
}

func TestGoTestImportErrorStack(t *testing.T) {
	const out = `package testdep/p1 (test)
	imports testdep/p2
	imports testdep/p3: no buildable Go source files`

	tg := testgo(t)
	defer tg.cleanup()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("test", "testdep/p1")
	if !strings.Contains(tg.stderr.String(), out) {
		t.Fatalf("did not give full import stack:\n\n%s", tg.stderr.String())
	}
}

func TestGoGetUpdate(t *testing.T) {
	// golang.org/issue/9224.
	// The recursive updating was trying to walk to
	// former dependencies, not current ones.

	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))

	rewind := func() {
		tg.run("get", "github.com/rsc/go-get-issue-9224-cmd")
		cmd := exec.Command("git", "reset", "--hard", "HEAD~")
		cmd.Dir = tg.path("src/github.com/rsc/go-get-issue-9224-lib")
		out, err := cmd.CombinedOutput()
		if err != nil {
			t.Fatalf("git: %v\n%s", err, out)
		}
	}

	rewind()
	tg.run("get", "-u", "github.com/rsc/go-get-issue-9224-cmd")

	// Again with -d -u.
	rewind()
	tg.run("get", "-d", "-u", "github.com/rsc/go-get-issue-9224-cmd")
}

func TestGoGetDomainRoot(t *testing.T) {
	// golang.org/issue/9357.
	// go get foo.io (not foo.io/subdir) was not working consistently.

	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))

	// go-get-issue-9357.appspot.com is running
	// the code at github.com/rsc/go-get-issue-9357,
	// a trivial Go on App Engine app that serves a
	// <meta> tag for the domain root.
	tg.run("get", "-d", "go-get-issue-9357.appspot.com")
	tg.run("get", "go-get-issue-9357.appspot.com")
	tg.run("get", "-u", "go-get-issue-9357.appspot.com")

	tg.must(os.RemoveAll(tg.path("src/go-get-issue-9357.appspot.com")))
	tg.run("get", "go-get-issue-9357.appspot.com")

	tg.must(os.RemoveAll(tg.path("src/go-get-issue-9357.appspot.com")))
	tg.run("get", "-u", "go-get-issue-9357.appspot.com")
}

func TestGoInstallShadowedGOPATH(t *testing.T) {
	// golang.org/issue/3652.
	// go get foo.io (not foo.io/subdir) was not working consistently.

	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("gopath1")+string(filepath.ListSeparator)+tg.path("gopath2"))

	tg.tempDir("gopath1/src/test")
	tg.tempDir("gopath2/src/test")
	tg.tempFile("gopath2/src/test/main.go", "package main\nfunc main(){}\n")

	tg.cd(tg.path("gopath2/src/test"))
	tg.runFail("install")
	tg.grepStderr("no install location for.*gopath2.src.test: hidden by .*gopath1.src.test", "missing error")
}

func TestGoBuildGOPATHOrder(t *testing.T) {
	// golang.org/issue/14176#issuecomment-179895769
	// golang.org/issue/14192
	// -I arguments to compiler could end up not in GOPATH order,
	// leading to unexpected import resolution in the compiler.
	// This is still not a complete fix (see golang.org/issue/14271 and next test)
	// but it is clearly OK and enough to fix both of the two reported
	// instances of the underlying problem. It will have to do for now.

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("p1")+string(filepath.ListSeparator)+tg.path("p2"))

	tg.tempFile("p1/src/foo/foo.go", "package foo\n")
	tg.tempFile("p2/src/baz/baz.go", "package baz\n")
	tg.tempFile("p2/pkg/"+runtime.GOOS+"_"+runtime.GOARCH+"/foo.a", "bad\n")
	tg.tempFile("p1/src/bar/bar.go", `
		package bar
		import _ "baz"
		import _ "foo"
	`)

	tg.run("install", "-x", "bar")
}

func TestGoBuildGOPATHOrderBroken(t *testing.T) {
	// This test is known not to work.
	// See golang.org/issue/14271.
	t.Skip("golang.org/issue/14271")

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()

	tg.tempFile("p1/src/foo/foo.go", "package foo\n")
	tg.tempFile("p2/src/baz/baz.go", "package baz\n")
	tg.tempFile("p1/pkg/"+runtime.GOOS+"_"+runtime.GOARCH+"/baz.a", "bad\n")
	tg.tempFile("p2/pkg/"+runtime.GOOS+"_"+runtime.GOARCH+"/foo.a", "bad\n")
	tg.tempFile("p1/src/bar/bar.go", `
		package bar
		import _ "baz"
		import _ "foo"
	`)

	colon := string(filepath.ListSeparator)
	tg.setenv("GOPATH", tg.path("p1")+colon+tg.path("p2"))
	tg.run("install", "-x", "bar")

	tg.setenv("GOPATH", tg.path("p2")+colon+tg.path("p1"))
	tg.run("install", "-x", "bar")
}

func TestIssue11709(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.tempFile("run.go", `
		package main
		import "os"
		func main() {
			if os.Getenv("TERM") != "" {
				os.Exit(1)
			}
		}`)
	tg.unsetenv("TERM")
	tg.run("run", tg.path("run.go"))
}

func TestIssue12096(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.tempFile("test_test.go", `
		package main
		import ("os"; "testing")
		func TestEnv(t *testing.T) {
			if os.Getenv("TERM") != "" {
				t.Fatal("TERM is set")
			}
		}`)
	tg.unsetenv("TERM")
	tg.run("test", tg.path("test_test.go"))
}

func TestGoBuildOutput(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()

	tg.makeTempdir()
	tg.cd(tg.path("."))

	nonExeSuffix := ".exe"
	if exeSuffix == ".exe" {
		nonExeSuffix = ""
	}

	tg.tempFile("x.go", "package main\nfunc main(){}\n")
	tg.run("build", "x.go")
	tg.wantExecutable("x"+exeSuffix, "go build x.go did not write x"+exeSuffix)
	tg.must(os.Remove(tg.path("x" + exeSuffix)))
	tg.mustNotExist("x" + nonExeSuffix)

	tg.run("build", "-o", "myprog", "x.go")
	tg.mustNotExist("x")
	tg.mustNotExist("x.exe")
	tg.wantExecutable("myprog", "go build -o myprog x.go did not write myprog")
	tg.mustNotExist("myprog.exe")

	tg.tempFile("p.go", "package p\n")
	tg.run("build", "p.go")
	tg.mustNotExist("p")
	tg.mustNotExist("p.a")
	tg.mustNotExist("p.o")
	tg.mustNotExist("p.exe")

	tg.run("build", "-o", "p.a", "p.go")
	tg.wantArchive("p.a")

	tg.run("build", "cmd/gofmt")
	tg.wantExecutable("gofmt"+exeSuffix, "go build cmd/gofmt did not write gofmt"+exeSuffix)
	tg.must(os.Remove(tg.path("gofmt" + exeSuffix)))
	tg.mustNotExist("gofmt" + nonExeSuffix)

	tg.run("build", "-o", "mygofmt", "cmd/gofmt")
	tg.wantExecutable("mygofmt", "go build -o mygofmt cmd/gofmt did not write mygofmt")
	tg.mustNotExist("mygofmt.exe")
	tg.mustNotExist("gofmt")
	tg.mustNotExist("gofmt.exe")

	tg.run("build", "sync/atomic")
	tg.mustNotExist("atomic")
	tg.mustNotExist("atomic.exe")

	tg.run("build", "-o", "myatomic.a", "sync/atomic")
	tg.wantArchive("myatomic.a")
	tg.mustNotExist("atomic")
	tg.mustNotExist("atomic.a")
	tg.mustNotExist("atomic.exe")

	tg.runFail("build", "-o", "whatever", "cmd/gofmt", "sync/atomic")
	tg.grepStderr("multiple packages", "did not reject -o with multiple packages")
}

func TestGoBuildARM(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping cross-compile in short mode")
	}

	tg := testgo(t)
	defer tg.cleanup()

	tg.makeTempdir()
	tg.cd(tg.path("."))

	tg.setenv("GOARCH", "arm")
	tg.setenv("GOOS", "linux")
	tg.setenv("GOARM", "5")
	tg.tempFile("hello.go", `package main
		func main() {}`)
	tg.run("build", "hello.go")
	tg.grepStderrNot("unable to find math.a", "did not build math.a correctly")
}

func TestIssue13655(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	for _, pkg := range []string{"runtime", "runtime/internal/atomic"} {
		tg.run("list", "-f", "{{.Deps}}", pkg)
		tg.grepStdout("runtime/internal/sys", "did not find required dependency of "+pkg+" on runtime/internal/sys")
	}
}

// For issue 14337.
func TestParallelTest(t *testing.T) {
	tg := testgo(t)
	tg.parallel()
	defer tg.cleanup()
	tg.makeTempdir()
	const testSrc = `package package_test
		import (
			"testing"
		)
		func TestTest(t *testing.T) {
		}`
	tg.tempFile("src/p1/p1_test.go", strings.Replace(testSrc, "package_test", "p1_test", 1))
	tg.tempFile("src/p2/p2_test.go", strings.Replace(testSrc, "package_test", "p2_test", 1))
	tg.tempFile("src/p3/p3_test.go", strings.Replace(testSrc, "package_test", "p3_test", 1))
	tg.tempFile("src/p4/p4_test.go", strings.Replace(testSrc, "package_test", "p4_test", 1))
	tg.setenv("GOPATH", tg.path("."))
	tg.run("test", "-p=4", "p1", "p2", "p3", "p4")
}

func TestCgoConsistentResults(t *testing.T) {
	if !canCgo {
		t.Skip("skipping because cgo not enabled")
	}
	switch runtime.GOOS {
	case "freebsd":
		testenv.SkipFlaky(t, 15405)
	case "solaris":
		testenv.SkipFlaky(t, 13247)
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.makeTempdir()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	exe1 := tg.path("cgotest1" + exeSuffix)
	exe2 := tg.path("cgotest2" + exeSuffix)
	tg.run("build", "-o", exe1, "cgotest")
	tg.run("build", "-x", "-o", exe2, "cgotest")
	b1, err := ioutil.ReadFile(exe1)
	tg.must(err)
	b2, err := ioutil.ReadFile(exe2)
	tg.must(err)

	if !tg.doGrepMatch(`-fdebug-prefix-map=\$WORK`, &tg.stderr) {
		t.Skip("skipping because C compiler does not support -fdebug-prefix-map")
	}
	if !bytes.Equal(b1, b2) {
		t.Error("building cgotest twice did not produce the same output")
	}
}

// Issue 14444: go get -u .../ duplicate loads errors
func TestGoGetUpdateAllDoesNotTryToLoadDuplicates(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))
	tg.run("get", "-u", ".../")
	tg.grepStderrNot("duplicate loads of", "did not remove old packages from cache")
}

// Issue 17119 more duplicate load errors
func TestIssue17119(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("build", "dupload")
	tg.grepBothNot("duplicate load|internal error", "internal error")
}

func TestFatalInBenchmarkCauseNonZeroExitStatus(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.runFail("test", "-run", "^$", "-bench", ".", "./testdata/src/benchfatal")
	tg.grepBothNot("^ok", "test passed unexpectedly")
	tg.grepBoth("FAIL.*benchfatal", "test did not run everything")
}

func TestBinaryOnlyPackages(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))

	tg.tempFile("src/p1/p1.go", `//go:binary-only-package

		package p1
	`)
	tg.wantStale("p1", "cannot access install target", "p1 is binary-only but has no binary, should be stale")
	tg.runFail("install", "p1")
	tg.grepStderr("missing or invalid package binary", "did not report attempt to compile binary-only package")

	tg.tempFile("src/p1/p1.go", `
		package p1
		import "fmt"
		func F(b bool) { fmt.Printf("hello from p1\n"); if b { F(false) } }
	`)
	tg.run("install", "p1")
	os.Remove(tg.path("src/p1/p1.go"))
	tg.mustNotExist(tg.path("src/p1/p1.go"))

	tg.tempFile("src/p2/p2.go", `//go:binary-only-packages-are-not-great

		package p2
		import "p1"
		func F() { p1.F(true) }
	`)
	tg.runFail("install", "p2")
	tg.grepStderr("no buildable Go source files", "did not complain about missing sources")

	tg.tempFile("src/p1/missing.go", `//go:binary-only-package

		package p1
		func G()
	`)
	tg.wantNotStale("p1", "no source code", "should NOT want to rebuild p1 (first)")
	tg.run("install", "-x", "p1") // no-op, up to date
	tg.grepBothNot("/compile", "should not have run compiler")
	tg.run("install", "p2") // does not rebuild p1 (or else p2 will fail)
	tg.wantNotStale("p2", "", "should NOT want to rebuild p2")

	// changes to the non-source-code do not matter,
	// and only one file needs the special comment.
	tg.tempFile("src/p1/missing2.go", `
		package p1
		func H()
	`)
	tg.wantNotStale("p1", "no source code", "should NOT want to rebuild p1 (second)")
	tg.wantNotStale("p2", "", "should NOT want to rebuild p2")

	tg.tempFile("src/p3/p3.go", `
		package main
		import (
			"p1"
			"p2"
		)
		func main() {
			p1.F(false)
			p2.F()
		}
	`)
	tg.run("install", "p3")

	tg.run("run", tg.path("src/p3/p3.go"))
	tg.grepStdout("hello from p1", "did not see message from p1")

	tg.tempFile("src/p4/p4.go", `package main`)
	tg.tempFile("src/p4/p4not.go", `//go:binary-only-package

		// +build asdf

		package main
	`)
	tg.run("list", "-f", "{{.BinaryOnly}}", "p4")
	tg.grepStdout("false", "did not see BinaryOnly=false for p4")
}

// Issue 16050.
func TestAlwaysLinkSysoFiles(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("src/syso")
	tg.tempFile("src/syso/a.syso", ``)
	tg.tempFile("src/syso/b.go", `package syso`)
	tg.setenv("GOPATH", tg.path("."))

	// We should see the .syso file regardless of the setting of
	// CGO_ENABLED.

	tg.setenv("CGO_ENABLED", "1")
	tg.run("list", "-f", "{{.SysoFiles}}", "syso")
	tg.grepStdout("a.syso", "missing syso file with CGO_ENABLED=1")

	tg.setenv("CGO_ENABLED", "0")
	tg.run("list", "-f", "{{.SysoFiles}}", "syso")
	tg.grepStdout("a.syso", "missing syso file with CGO_ENABLED=0")
}

// Issue 16120.
func TestGenerateUsesBuildContext(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("this test won't run under Windows")
	}

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.tempDir("src/gen")
	tg.tempFile("src/gen/gen.go", "package gen\n//go:generate echo $GOOS $GOARCH\n")
	tg.setenv("GOPATH", tg.path("."))

	tg.setenv("GOOS", "linux")
	tg.setenv("GOARCH", "amd64")
	tg.run("generate", "gen")
	tg.grepStdout("linux amd64", "unexpected GOOS/GOARCH combination")

	tg.setenv("GOOS", "darwin")
	tg.setenv("GOARCH", "386")
	tg.run("generate", "gen")
	tg.grepStdout("darwin 386", "unexpected GOOS/GOARCH combination")
}

// Issue 14450: go get -u .../ tried to import not downloaded package
func TestGoGetUpdateWithWildcard(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.makeTempdir()
	tg.setenv("GOPATH", tg.path("."))
	const aPkgImportPath = "github.com/tmwh/go-get-issue-14450/a"
	tg.run("get", aPkgImportPath)
	tg.run("get", "-u", ".../")
	tg.grepStderrNot("cannot find package", "did not update packages given wildcard path")

	var expectedPkgPaths = []string{
		"src/github.com/tmwh/go-get-issue-14450/b",
		"src/github.com/tmwh/go-get-issue-14450-b-dependency/c",
		"src/github.com/tmwh/go-get-issue-14450-b-dependency/d",
	}

	for _, importPath := range expectedPkgPaths {
		_, err := os.Stat(tg.path(importPath))
		tg.must(err)
	}
	const notExpectedPkgPath = "src/github.com/tmwh/go-get-issue-14450-c-dependency/e"
	tg.mustNotExist(tg.path(notExpectedPkgPath))
}

func TestGoEnv(t *testing.T) {
	tg := testgo(t)
	tg.parallel()
	defer tg.cleanup()
	tg.setenv("GOARCH", "arm")
	tg.run("env", "GOARCH")
	tg.grepStdout("^arm$", "GOARCH not honored")

	tg.run("env", "GCCGO")
	tg.grepStdout(".", "GCCGO unexpectedly empty")

	tg.run("env", "CGO_CFLAGS")
	tg.grepStdout(".", "default CGO_CFLAGS unexpectedly empty")

	tg.setenv("CGO_CFLAGS", "-foobar")
	tg.run("env", "CGO_CFLAGS")
	tg.grepStdout("^-foobar$", "CGO_CFLAGS not honored")

	tg.setenv("CC", "gcc -fmust -fgo -ffaster")
	tg.run("env", "CC")
	tg.grepStdout("gcc", "CC not found")
	tg.run("env", "GOGCCFLAGS")
	tg.grepStdout("-ffaster", "CC arguments not found")
}

const (
	noMatchesPattern = `(?m)^ok.*\[no tests to run\]`
	okPattern        = `(?m)^ok`
)

func TestMatchesNoTests(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.run("test", "-run", "ThisWillNotMatch", "testdata/standalone_test.go")
	tg.grepBoth(noMatchesPattern, "go test did not say [no tests to run]")
}

func TestMatchesNoTestsDoesNotOverrideBuildFailure(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	tg.runFail("test", "-run", "ThisWillNotMatch", "syntaxerror")
	tg.grepBothNot(noMatchesPattern, "go test did say [no tests to run]")
	tg.grepBoth("FAIL", "go test did not say FAIL")
}

func TestMatchesNoBenchmarksIsOK(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.run("test", "-run", "^$", "-bench", "ThisWillNotMatch", "testdata/standalone_benchmark_test.go")
	tg.grepBothNot(noMatchesPattern, "go test did say [no tests to run]")
	tg.grepBoth(okPattern, "go test did not say ok")
}

func TestMatchesOnlyExampleIsOK(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.run("test", "-run", "Example", "testdata/example1_test.go")
	tg.grepBothNot(noMatchesPattern, "go test did say [no tests to run]")
	tg.grepBoth(okPattern, "go test did not say ok")
}

func TestMatchesOnlyBenchmarkIsOK(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.run("test", "-run", "^$", "-bench", ".", "testdata/standalone_benchmark_test.go")
	tg.grepBothNot(noMatchesPattern, "go test did say [no tests to run]")
	tg.grepBoth(okPattern, "go test did not say ok")
}

func TestMatchesOnlyTestIsOK(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	// TODO: tg.parallel()
	tg.run("test", "-run", "Test", "testdata/standalone_test.go")
	tg.grepBothNot(noMatchesPattern, "go test did say [no tests to run]")
	tg.grepBoth(okPattern, "go test did not say ok")
}

func TestMatchesNoTestsWithSubtests(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "-run", "ThisWillNotMatch", "testdata/standalone_sub_test.go")
	tg.grepBoth(noMatchesPattern, "go test did not say [no tests to run]")
}

func TestMatchesNoSubtestsMatch(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "-run", "Test/ThisWillNotMatch", "testdata/standalone_sub_test.go")
	tg.grepBoth(noMatchesPattern, "go test did not say [no tests to run]")
}

func TestMatchesNoSubtestsDoesNotOverrideFailure(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.runFail("test", "-run", "TestThatFails/ThisWillNotMatch", "testdata/standalone_fail_sub_test.go")
	tg.grepBothNot(noMatchesPattern, "go test did say [no tests to run]")
	tg.grepBoth("FAIL", "go test did not say FAIL")
}

func TestMatchesOnlySubtestIsOK(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "-run", "Test/Sub", "testdata/standalone_sub_test.go")
	tg.grepBothNot(noMatchesPattern, "go test did say [no tests to run]")
	tg.grepBoth(okPattern, "go test did not say ok")
}

func TestMatchesNoSubtestsParallel(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "-run", "Test/Sub/ThisWillNotMatch", "testdata/standalone_parallel_sub_test.go")
	tg.grepBoth(noMatchesPattern, "go test did not say [no tests to run]")
}

func TestMatchesOnlySubtestParallelIsOK(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "-run", "Test/Sub/Nested", "testdata/standalone_parallel_sub_test.go")
	tg.grepBothNot(noMatchesPattern, "go test did say [no tests to run]")
	tg.grepBoth(okPattern, "go test did not say ok")
}

// Issue 18845
func TestBenchTimeout(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.run("test", "-bench", ".", "-timeout", "750ms", "testdata/timeoutbench_test.go")
}

func TestLinkXImportPathEscape(t *testing.T) {
	// golang.org/issue/16710
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
	exe := "./linkx" + exeSuffix
	tg.creatingTemp(exe)
	tg.run("build", "-o", exe, "-ldflags", "-X=my.pkg.Text=linkXworked", "my.pkg/main")
	out, err := exec.Command(exe).CombinedOutput()
	if err != nil {
		tg.t.Fatal(err)
	}
	if string(out) != "linkXworked\n" {
		tg.t.Log(string(out))
		tg.t.Fatal(`incorrect output: expected "linkXworked\n"`)
	}
}

// Issue 18044.
func TestLdBindNow(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	tg.setenv("LD_BIND_NOW", "1")
	tg.run("help")
}

// Issue 18225.
// This is really a cmd/asm issue but this is a convenient place to test it.
func TestConcurrentAsm(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()
	tg.parallel()
	asm := `DATA ·constants<>+0x0(SB)/8,$0
GLOBL ·constants<>(SB),8,$8
`
	tg.tempFile("go/src/p/a.s", asm)
	tg.tempFile("go/src/p/b.s", asm)
	tg.tempFile("go/src/p/p.go", `package p`)
	tg.setenv("GOPATH", tg.path("go"))
	tg.run("build", "p")
}

// Issue 18778.
func TestDotDotDotOutsideGOPATH(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()

	tg.tempFile("pkgs/a.go", `package x`)
	tg.tempFile("pkgs/a_test.go", `package x_test
import "testing"
func TestX(t *testing.T) {}`)

	tg.tempFile("pkgs/a/a.go", `package a`)
	tg.tempFile("pkgs/a/a_test.go", `package a_test
import "testing"
func TestA(t *testing.T) {}`)

	tg.cd(tg.path("pkgs"))
	tg.run("build", "./...")
	tg.run("test", "./...")
	tg.run("list", "./...")
	tg.grepStdout("pkgs$", "expected package not listed")
	tg.grepStdout("pkgs/a", "expected package not listed")
}

func TestBadCommandLines(t *testing.T) {
	tg := testgo(t)
	defer tg.cleanup()

	tg.tempFile("src/x/x.go", "package x\n")
	tg.setenv("GOPATH", tg.path("."))

	tg.run("build", "x")

	tg.tempFile("src/x/@y.go", "package x\n")
	tg.runFail("build", "x")
	tg.grepStderr("invalid input file name \"@y.go\"", "did not reject @y.go")
	tg.must(os.Remove(tg.path("src/x/@y.go")))

	tg.tempFile("src/x/-y.go", "package x\n")
	tg.runFail("build", "x")
	tg.grepStderr("invalid input file name \"-y.go\"", "did not reject -y.go")
	tg.must(os.Remove(tg.path("src/x/-y.go")))

	tg.runFail("build", "-gcflags=@x", "x")
	tg.grepStderr("invalid command-line argument @x in command", "did not reject @x during exec")

	tg.tempFile("src/@x/x.go", "package x\n")
	tg.setenv("GOPATH", tg.path("."))
	tg.runFail("build", "@x")
	tg.grepStderr("invalid input directory name \"@x\"", "did not reject @x directory")

	tg.tempFile("src/@x/y/y.go", "package y\n")
	tg.setenv("GOPATH", tg.path("."))
	tg.runFail("build", "@x/y")
	tg.grepStderr("invalid import path \"@x/y\"", "did not reject @x/y import path")

	tg.tempFile("src/-x/x.go", "package x\n")
	tg.setenv("GOPATH", tg.path("."))
	tg.runFail("build", "--", "-x")
	tg.grepStderr("invalid input directory name \"-x\"", "did not reject -x directory")

	tg.tempFile("src/-x/y/y.go", "package y\n")
	tg.setenv("GOPATH", tg.path("."))
	tg.runFail("build", "--", "-x/y")
	tg.grepStderr("invalid import path \"-x/y\"", "did not reject -x/y import path")
}

func TestBadCgoDirectives(t *testing.T) {
	if !canCgo {
		t.Skip("no cgo")
	}
	tg := testgo(t)
	defer tg.cleanup()

	tg.tempFile("src/x/x.go", "package x\n")
	tg.setenv("GOPATH", tg.path("."))

	tg.tempFile("src/x/x.go", `package x

		//go:cgo_ldflag "-fplugin=foo.so"

	`)
	tg.runFail("build", "x")
	tg.grepStderr("//go:cgo_ldflag .* only allowed in cgo-generated code", "did not reject //go:cgo_ldflag directive")

	tg.must(os.Remove(tg.path("src/x/x.go")))
	tg.runFail("build", "x")
	tg.grepStderr("no buildable Go source files", "did not report missing source code")
	tg.tempFile("src/x/_cgo_yy.go", `package x

		//go:cgo_ldflag "-fplugin=foo.so"

	`)
	tg.runFail("build", "x")
	tg.grepStderr("no buildable Go source files", "did not report missing source code") // _* files are ignored...

	tg.runFail("build", tg.path("src/x/_cgo_yy.go")) // ... but if forced, the comment is rejected
	// Actually, today there is a separate issue that _ files named
	// on the command-line are ignored. Once that is fixed,
	// we want to see the cgo_ldflag error.
	tg.grepStderr("//go:cgo_ldflag only allowed in cgo-generated code|no buildable Go source files", "did not reject //go:cgo_ldflag directive")
	tg.must(os.Remove(tg.path("src/x/_cgo_yy.go")))

	tg.tempFile("src/x/x.go", "package x\n")
	tg.tempFile("src/x/y.go", `package x
		// #cgo CFLAGS: -fplugin=foo.so
		import "C"
	`)
	tg.runFail("build", "x")
	tg.grepStderr("invalid flag in #cgo CFLAGS: -fplugin=foo.so", "did not reject -fplugin")

	tg.tempFile("src/x/y.go", `package x
		// #cgo CFLAGS: -Ibar -fplugin=foo.so
		import "C"
	`)
	tg.runFail("build", "x")
	tg.grepStderr("invalid flag in #cgo CFLAGS: -fplugin=foo.so", "did not reject -fplugin")

	tg.tempFile("src/x/y.go", `package x
		// #cgo pkg-config: -foo
		import "C"
	`)
	tg.runFail("build", "x")
	tg.grepStderr("invalid pkg-config package name: -foo", "did not reject pkg-config: -foo")

	tg.tempFile("src/x/y.go", `package x
		// #cgo pkg-config: @foo
		import "C"
	`)
	tg.runFail("build", "x")
	tg.grepStderr("invalid pkg-config package name: @foo", "did not reject pkg-config: -foo")

	tg.tempFile("src/x/y.go", `package x
		// #cgo CFLAGS: @foo
		import "C"
	`)
	tg.runFail("build", "x")
	tg.grepStderr("invalid flag in #cgo CFLAGS: @foo", "did not reject @foo flag")

	tg.tempFile("src/x/y.go", `package x
		// #cgo CFLAGS: -D
		import "C"
	`)
	tg.runFail("build", "x")
	tg.grepStderr("invalid flag in #cgo CFLAGS: -D without argument", "did not reject trailing -I flag")

	// Note that -I @foo is allowed because we rewrite it into -I /path/to/src/@foo
	// before the check is applied. There's no such rewrite for -D.

	tg.tempFile("src/x/y.go", `package x
		// #cgo CFLAGS: -D @foo
		import "C"
	`)
	tg.runFail("build", "x")
	tg.grepStderr("invalid flag in #cgo CFLAGS: -D @foo", "did not reject -D @foo flag")

	tg.tempFile("src/x/y.go", `package x
		// #cgo CFLAGS: -D@foo
		import "C"
	`)
	tg.runFail("build", "x")
	tg.grepStderr("invalid flag in #cgo CFLAGS: -D@foo", "did not reject -D@foo flag")

	tg.setenv("CGO_CFLAGS", "-D@foo")
	tg.tempFile("src/x/y.go", `package x
		import "C"
	`)
	tg.run("build", "-n", "x")
	tg.grepStderr("-D@foo", "did not find -D@foo in commands")
}