src/cmd/go/testdata/script/env_write.txt

env GO111MODULE=off

# go env should default to the right places
env AppData=$HOME/windowsappdata
env home=$HOME/plan9home
go env GOENV
[aix] stdout $HOME/.config/go/env
[darwin] stdout $HOME'/Library/Application Support/go/env'
[freebsd] stdout $HOME/.config/go/env
[linux] stdout $HOME/.config/go/env
[netbsd] stdout $HOME/.config/go/env
[openbsd] stdout $HOME/.config/go/env
[plan9] stdout $HOME/plan9home/lib/go/env
[windows] stdout $HOME\\windowsappdata\\go\\env

# Now override it to something writable.
env GOENV=$WORK/envdir/go/env
go env GOENV
stdout envdir[\\/]go[\\/]env

# go env shows all variables
go env
stdout GOARCH=
stdout GOOS=
stdout GOROOT=

# go env ignores invalid flag in GOFLAGS environment variable
env GOFLAGS='=true'
go env

# checking errors
! go env -w
stderr 'go env -w: no KEY=VALUE arguments given'
! go env -u
stderr 'go env -u: no arguments given'

# go env -w changes default setting
env root=
[windows] env root=c:
env GOPATH=
go env -w GOPATH=$root/non-exist/gopath
! stderr .+
grep GOPATH=$root/non-exist/gopath $WORK/envdir/go/env
go env GOPATH
stdout /non-exist/gopath

# go env -w does not override OS environment, and warns about that
env GOPATH=$root/other
go env -w GOPATH=$root/non-exist/gopath2
stderr 'warning: go env -w GOPATH=... does not override conflicting OS environment variable'
go env GOPATH
stdout $root/other

# but go env -w does do the update, and unsetting the env var exposes the change
env GOPATH=
go env GOPATH
stdout $root/non-exist/gopath2

# unsetting with go env -u does not warn about OS environment overrides,
# nor does it warn about variables that haven't been set by go env -w.
env GOPATH=$root/other
go env -u GOPATH
! stderr .+
go env -u GOPATH
! stderr .+

# go env -w rejects unknown or bad variables
! go env -w GODEBUG=gctrace=1
stderr 'unknown go command variable GODEBUG'
! go env -w GOEXE=.bat
stderr 'GOEXE cannot be modified'
! go env -w GOVERSION=customversion
stderr 'GOVERSION cannot be modified'
! go env -w GOENV=/env
stderr 'GOENV can only be set using the OS environment'

# go env -w can set multiple variables
env CC=
go env CC
! stdout ^xyc$
go env -w GOOS=$GOOS CC=xyc
grep CC=xyc $GOENV
# file is maintained in sorted order
grep 'CC=xyc\nGOOS=' $GOENV
go env CC
stdout ^xyc$

# go env -u unsets effect of go env -w.
go env -u CC
go env CC
! stdout ^xyc$

# go env -w rejects double-set variables
! go env -w GOOS=$GOOS GOOS=$GOOS
stderr 'multiple values for key: GOOS'

# go env -w rejects missing variables
! go env -w GOOS
stderr 'arguments must be KEY=VALUE: invalid argument: GOOS'

# go env -w rejects invalid GO111MODULE values, as otherwise cmd/go would break
! go env -w GO111MODULE=badvalue
stderr 'invalid GO111MODULE value "badvalue"'

# go env -w rejects invalid GOPATH values
! go env -w GOPATH=~/go
stderr 'GOPATH entry cannot start with shell metacharacter'

! go env -w GOPATH=./go
stderr 'GOPATH entry is relative; must be absolute path'

# go env -w rejects invalid GOTMPDIR values
! go env -w GOTMPDIR=x
stderr 'go env -w: GOTMPDIR must be an absolute path'

# go env -w should accept absolute GOTMPDIR value
# and should not create it
[windows] go env -w GOTMPDIR=$WORK\x\y\z
[!windows] go env -w GOTMPDIR=$WORK/x/y/z
! exists $WORK/x/y/z
# we should be able to clear an env
go env -u GOTMPDIR
go env GOTMPDIR
stdout ^$

[windows] go env -w GOTMPDIR=$WORK\x\y\z
[!windows] go env -w GOTMPDIR=$WORK/x/y/z
go env -w GOTMPDIR=
go env GOTMPDIR
stdout ^$

# go env -w rejects relative CC values
[!windows] go env -w CC=/usr/bin/clang
go env -w CC=clang
[!windows] ! go env -w CC=./clang
[!windows] ! go env -w CC=bin/clang
[!windows] stderr 'go env -w: CC entry is relative; must be absolute path'

[windows] go env -w CC=$WORK\bin\clang
[windows] ! go env -w CC=.\clang
[windows] ! go env -w CC=bin\clang
[windows] stderr 'go env -w: CC entry is relative; must be absolute path'

# go env -w rejects relative CXX values
[!windows] go env -w CC=/usr/bin/cpp
go env -w CXX=cpp
[!windows] ! go env -w CXX=./cpp
[!windows] ! go env -w CXX=bin/cpp
[!windows] stderr 'go env -w: CXX entry is relative; must be absolute path'

[windows] go env -w CXX=$WORK\bin\cpp
[windows] ! go env -w CXX=.\cpp
[windows] ! go env -w CXX=bin\cpp
[windows] stderr 'go env -w: CXX entry is relative; must be absolute path'

# go env -w/-u checks validity of GOOS/ARCH combinations
env GOOS=
env GOARCH=
# check -w doesn't allow invalid GOOS
! go env -w GOOS=linuxx
stderr 'unsupported GOOS/GOARCH pair linuxx'
# check -w doesn't allow invalid GOARCH
! go env -w GOARCH=amd644
stderr 'unsupported GOOS/GOARCH.*/amd644$'
# check -w doesn't allow invalid GOOS with valid GOARCH
! go env -w GOOS=linuxx GOARCH=amd64
stderr 'unsupported GOOS/GOARCH pair linuxx'
# check a valid GOOS and GOARCH values but an incompatible combinations
! go env -w GOOS=android GOARCH=s390x
stderr 'unsupported GOOS/GOARCH pair android/s390x'
# check that -u considers explicit envs
go env -w GOOS=linux GOARCH=mips
env GOOS=windows
! go env -u GOOS
stderr 'unsupported GOOS/GOARCH.*windows/mips$'

# go env -w should reject relative paths in GOMODCACHE environment.
! go env -w GOMODCACHE=~/test
stderr 'go env -w: GOMODCACHE entry is relative; must be absolute path: "~/test"'
! go env -w GOMODCACHE=./test
stderr 'go env -w: GOMODCACHE entry is relative; must be absolute path: "./test"'

# go env -w checks validity of GOEXPERIMENT
env GOEXPERIMENT=
! go env -w GOEXPERIMENT=badexp
stderr 'unknown GOEXPERIMENT badexp'
go env -w GOEXPERIMENT=fieldtrack