# Regression test for https://go.dev/issue/64282.
#
# 'go install' and 'go run' with pkg@version arguments should make
# a best effort to parse flags relevant to downloading modules
# (currently only -modcacherw) before actually downloading the module
# to identify which toolchain version to use.
#
# However, the best-effort flag parsing should not interfere with
# actual flag parsing if we don't switch toolchains. In particular,
# unrecognized flags should still be diagnosed after the module for
# the requested package has been downloaded and checked for toolchain
# upgrades.


! go install -cake=delicious -modcacherw example.com/printversion@v0.1.0
stderr '^flag provided but not defined: -cake$'
	# Because the -modcacherw flag was set, we should be able to modify the contents
	# of a directory within the module cache.
cp $WORK/extraneous.txt $GOPATH/pkg/mod/example.com/printversion@v0.1.0/extraneous_file.go
go clean -modcache


! go install -unknownflag -tags -modcacherw example.com/printversion@v0.1.0
stderr '^flag provided but not defined: -unknownflag$'
cp $WORK/extraneous.txt $GOPATH/pkg/mod/example.com/printversion@v0.1.0/extraneous_file.go
go clean -modcache


# Also try it with a 'go install' that succeeds.
# (But skip in short mode, because linking a binary is expensive.)
[!short] go install -modcacherw example.com/printversion@v0.1.0
[!short] cp $WORK/extraneous.txt $GOPATH/pkg/mod/example.com/printversion@v0.1.0/extraneous_file.go
[!short] go clean -modcache


# The flag should also be applied if given in GOFLAGS
# instead of on the command line.
env GOFLAGS=-modcacherw
! go install -cake=delicious example.com/printversion@v0.1.0
stderr '^flag provided but not defined: -cake$'
cp $WORK/extraneous.txt $GOPATH/pkg/mod/example.com/printversion@v0.1.0/extraneous_file.go


-- $WORK/extraneous.txt --
This is not a Go source file.