cmd/go: place GOROOT/bin at the beginning of PATH in 'go run'

This causes programs that use 'go' as a subprocess to use the same go
command as the parent 'go run' command.

Fixes #68005

Change-Id: I937cef474bf038a925bb74fc73e5f377b03e27b7
GitHub-Last-Rev: 9986537cadb0921763cc1496a63e3806b4aac1ac
GitHub-Pull-Request: golang/go#68040
Reviewed-on: https://go-review.googlesource.com/c/go/+/593255
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Matloob <matloob@golang.org>

diff --git a/src/cmd/go/internal/base/base.go b/src/cmd/go/internal/base/base.go
index 2171d139096a343c708450c613d80e923d8a7da4..0ba2ffd415fe431dd6cf5877ec643c8b26d8d05e 100644 (file)
--- a/src/cmd/go/internal/base/base.go
+++ b/src/cmd/go/internal/base/base.go
@@ -14,6 +14,7 @@ import (
        "os"
        "os/exec"
        "reflect"
+       "slices"
        "strings"
        "sync"
 
@@ -211,7 +212,9 @@ func RunStdin(cmdline []string) {
        cmd.Stdin = os.Stdin
        cmd.Stdout = os.Stdout
        cmd.Stderr = os.Stderr
-       cmd.Env = cfg.OrigEnv
+       env := slices.Clip(cfg.OrigEnv)
+       env = AppendPATH(env)
+       cmd.Env = env
        StartSigHandlers()
        if err := cmd.Run(); err != nil {
                Errorf("%v", err)

diff --git a/src/cmd/go/testdata/script/run_goroot_PATH.txt b/src/cmd/go/testdata/script/run_goroot_PATH.txt
new file mode 100644 (file)
index 0000000..a103cf6
--- /dev/null
+++ b/src/cmd/go/testdata/script/run_goroot_PATH.txt
@@ -0,0 +1,42 @@
+# https://go.dev/issue/68005: 'go run' should run the program with its own GOROOT/bin
+# at the beginning of $PATH.
+
+[short] skip
+
+[!GOOS:plan9] env PATH=
+[GOOS:plan9] env path=
+go run .
+
+[!GOOS:plan9] env PATH=$WORK${/}bin
+[GOOS:plan9] env path=$WORK${/}bin
+go run .
+
+-- go.mod --
+module example
+
+go 1.19
+-- main.go --
+package main
+
+import (
+       "fmt"
+       "os"
+       "os/exec"
+       "path/filepath"
+)
+
+func main() {
+       got, err := exec.LookPath("go")
+       if err != nil {
+               fmt.Println(err)
+               os.Exit(1)
+       }
+
+       want := filepath.Join(os.Getenv("GOROOT"), "bin", "go" + os.Getenv("GOEXE"))
+       if got != want {
+               fmt.Printf(`exec.LookPath("go") = %q; want %q\n`, got, want)
+               os.Exit(1)
+       }
+}
+-- $WORK/bin/README.txt --
+This directory contains no executables.