cmd/go/internal/modload: fail if no package was found in local module
Changing the Import function to return a PackageNotInModuleError if no
package was found in a local module. This replacing the vague message
"missing dot in first path element" you get today with much more friendly
one - "module was found, but does not contain package".
Fixes #35273
Change-Id: I6d726c17e6412258274b10f58f76621617d26e0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/203118
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
diff --git a/src/cmd/go/internal/modload/import.go b/src/cmd/go/internal/modload/import.go
index 8a18da3..a01ef62 100644
--- a/src/cmd/go/internal/modload/import.go
+++ b/src/cmd/go/internal/modload/import.go
@@ -237,6 +237,17 @@
return m, "", &ImportMissingError{Path: path, Module: m}
}
}
+ if len(mods) > 0 && module.CheckPath(path) != nil {
+ // The package path is not valid to fetch remotely,
+ // so it can only exist if in a replaced module,
+ // and we know from the above loop that it is not.
+ return module.Version{}, "", &PackageNotInModuleError{
+ Mod: mods[0],
+ Query: "latest",
+ Pattern: path,
+ Replacement: Replacement(mods[0]),
+ }
+ }
}
candidates, err := QueryPackage(path, "latest", Allowed)
diff --git a/src/cmd/go/testdata/script/mod_replace_import.txt b/src/cmd/go/testdata/script/mod_replace_import.txt
index 0da753a..941ef61 100644
--- a/src/cmd/go/testdata/script/mod_replace_import.txt
+++ b/src/cmd/go/testdata/script/mod_replace_import.txt
@@ -23,6 +23,13 @@
stdout 'example.com/x/v3 v3.0.0-00010101000000-000000000000 => ./v3'
stdout 'example.com/v v1.12.0 => ./v12'
+# The go command should print an informative error when the matched
+# module does not contain a package.
+cd fail
+! go list all
+stdout 'localhost.fail'
+stderr '^can.t load package: m.go:3:8: module w@latest found \(v0.0.0-00010101000000-000000000000, replaced by ../w\), but does not contain package w$'
+
-- go.mod --
module example.com/m
@@ -107,3 +114,16 @@
module v.localhost
-- v/v.go --
package v
+
+-- fail/m.go --
+package main
+
+import _ "w"
+
+func main() {}
+
+-- fail/go.mod --
+module localhost.fail
+
+replace w => ../w
+
