os/exec: The TestImplicitPWD test fails when running under a soft link folder.

[zhangfannie]

What version of Go are you using (go version)?

$ go version
go version devel go1.19-96c8cc7fea Sun Apr 24 01:22:21 2022 +0000 linux/arm64

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE="auto"
GOARCH="arm64"
GOBIN=""
GOCACHE="/home/fanzha02/.cache/go-build"
GOENV="/home/fanzha02/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="arm64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/fanzha02/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/fanzha02/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/fanzha02/sharefolder/golang"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/fanzha02/sharefolder/golang/pkg/tool/linux_arm64"
GOVCS=""
GOVERSION="devel go1.19-96c8cc7fea Sun Apr 24 01:22:21 2022 +0000"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/fanzha02/sharefolder/golang/src/go.mod"
GOWORK=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build1974904193=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Run the TestImplicitPWD test under a soft link folder.

What did you expect to see?

pass

What did you see instead?

~/sharefolder/golang/src/os/exec$ ../../../bin/go test -run=TestImplicitPWD
--- FAIL: TestImplicitPWD (0.00s)
--- FAIL: TestImplicitPWD/empty (0.00s)
exec_posix_test.go:161: in

        `pwd` reported
            /mnt/share/homes/fanzha02/golang/src/os/exec
    exec_posix_test.go:163: want
            /home/fanzha02/sharefolder/golang/src/os/exec
--- FAIL: TestImplicitPWD/PWD (0.00s)
    exec_posix_test.go:161: in
            /home/fanzha02/sharefolder/golang/src/os/exec
        `pwd` reported
            /mnt/share/homes/fanzha02/golang/src/os/exec
    exec_posix_test.go:163: want
            /home/fanzha02/sharefolder/golang/src/os/exec
--- FAIL: TestImplicitPWD/dot (0.02s)
    exec_posix_test.go:161: in
            .
        `pwd` reported
            /mnt/share/homes/fanzha02/golang/src/os/exec
    exec_posix_test.go:163: want
            /home/fanzha02/sharefolder/golang/src/os/exec
--- FAIL: TestImplicitPWD/dotdot (0.02s)
    exec_posix_test.go:161: in
            ..
        `pwd` reported
            /mnt/share/homes/fanzha02/golang/src/os
    exec_posix_test.go:163: want
            /home/fanzha02/sharefolder/golang/src/os
--- FAIL: TestImplicitPWD/PWDdotdot (0.02s)
    exec_posix_test.go:161: in
            /home/fanzha02/sharefolder/golang/src/os/exec/..
        `pwd` reported
            /mnt/share/homes/fanzha02/golang/src/os
    exec_posix_test.go:163: want
            /home/fanzha02/sharefolder/golang/src/os

FAIL
exit status 1

[zhangfannie]

The folder where I run the test is a soft link folder.

 > ls -all ~/sharefolder
 /home/fanzha02/sharefolder -> /mnt/share/homes/fanzha02

The TestImplicitPWD test is to compare whether the output of os.Getwd() and the output of exec.Command("pwd") are equal. When run it under a soft link folder, the os.Getwd() returns the directory of soft link folder, it is /home/fanzha02/sharefolder, the exec.Command("pwd") returns the directory of source folder, it is /mnt/share/homes/fanzha02, different outputs cause the test to fail.

I am not familar with the destination of the TestImplicitPWD test, is this failure expected? Thank you.

[zhangfannie]

@bcmills

[bcmills]

Heh, looks like /bin/pwd doesn't actually behave the same as the pwd built-in:

/tmp$ ln -s ~/go-review goroot-link

/tmp$ cd goroot-link/src/os/exec

/tmp/goroot-link/src/os/exec$ pwd
/tmp/goroot-link/src/os/exec

/tmp/goroot-link/src/os/exec$ /bin/pwd
/usr/local/google/home/bcmills/go-review/src/os/exec

This is fixed by CL 401934, but a more local fix seems possible.

[gopherbot]

Change https://go.dev/cl/402158 mentions this issue: os/exec: in TestImplicitPWD, explicitly request the logical path