list_goroot_symlink.txt

# Regression test for https://go.dev/issue/57754: 'go list' failed if ../src
# relative to the location of the go executable was a symlink to the real src
# directory. (cmd/go expects that ../src is GOROOT/src, but it appears that the
# Debian build of the Go toolchain is attempting to split GOROOT into binary and
# source artifacts in different parent directories.)

[short] skip 'copies the cmd/go binary'
[!symlink] skip 'tests symlink-specific behavior'

# Ensure that the relative path to $WORK/lib/goroot/src from $PWD is a different
# number of ".." hops than the relative path to it from $WORK/share/goroot/src.

cd $WORK

# Construct a fake GOROOT in $WORK/lib/goroot whose src directory is a symlink
# to a subdirectory of $WORK/share. This mimics the directory structure reported
# in https://go.dev/issue/57754.
#
# Symlink everything else to the original $GOROOT to avoid needless copying work.

mkdir $WORK/lib/goroot
mkdir $WORK/share/goroot
symlink $WORK/share/goroot/src -> $GOROOT${/}src
symlink $WORK/lib/goroot/src -> ../../share/goroot/src
symlink $WORK/lib/goroot/pkg -> $GOROOT${/}pkg

# Verify that our symlink shenanigans don't prevent cmd/go from finding its
# GOROOT using os.Executable.
#
# To do so, we copy the actual cmd/go executable — which is implemented as the
# cmd/go test binary instead of the original $GOROOT/bin/go, which may be
# arbitrarily stale — into the bin subdirectory of the fake GOROOT, causing
# os.Executable to report a path in that directory.

mkdir $WORK/lib/goroot/bin
cp $TESTGO_EXE $WORK/lib/goroot/bin/go$GOEXE

env GOROOT=''  # Clear to force cmd/go to find GOROOT itself.
exec $WORK/lib/goroot/bin/go env GOROOT
stdout $WORK${/}lib${/}goroot

# Now verify that 'go list' can find standard-library packages in the symlinked
# source tree, with paths matching the one reported by 'go env GOROOT'.

exec $WORK/lib/goroot/bin/go list -f '{{.ImportPath}}: {{.Dir}}' encoding/binary
stdout '^encoding/binary: '$WORK${/}lib${/}goroot${/}src${/}encoding${/}binary'$'

exec $WORK/lib/goroot/bin/go list -f '{{.ImportPath}}: {{.Dir}}' std
stdout '^encoding/binary: '$WORK${/}lib${/}goroot${/}src${/}encoding${/}binary'$'

# Most path lookups in GOROOT are not sensitive to symlinks. However, patterns
# involving '...' wildcards must use Walk to check the GOROOT tree, which makes
# them more sensitive to symlinks (because Walk doesn't follow them).
#
# So we check such a pattern to confirm that it works and reports a path relative
# to $GOROOT/src (and not the symlink target).

exec $WORK/lib/goroot/bin/go list -f '{{.ImportPath}}: {{.Dir}}' .../binary
stdout '^encoding/binary: '$WORK${/}lib${/}goroot${/}src${/}encoding${/}binary'$'
! stderr .