os/exec: No stderr is shown in the os/exec error

[finn-ball]

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

go version go1.15.7 linux/amd64

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=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/finn/.cache/go-build"
GOENV="/home/finn/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/finn/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/finn/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/lib/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build623746363=/tmp/go-build -gno-record-gcc-switches"

What did you do?

This doesn't run on the playground. Run this, for example, in a non-git directory.

The docs imply we should be able to see at least some of the stderr:
https://golang.org/src/os/exec/exec.go?s=6278:6323#L461

package main

import (
	"fmt"
	"os"
	"os/exec"
)

func main() {
	if err := execute(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

// Simple git execution.
func execute() error {
	cmd := exec.Command("git", "status")

	if err := cmd.Start(); err != nil {
		return err
	}

	if err := cmd.Wait(); err != nil {
		if e, ok := err.(*exec.ExitError); ok {
			fmt.Println(e)
			fmt.Println(string(e.Stderr))
		}
		return err
	}

	return nil
}

What did you expect to see?

The stderr.

What did you see instead?

Nothing.

[seankhliao]

The doc for os/exec.ExitError.Stderr says (emphasis added):

// Stderr holds a subset of the standard error output from the
// Cmd.Output method if standard error was not otherwise being
// collected.

No other methods are documented to store Stderr

Closing as working as intended