if p1.Stale && p1.StaleReason != "" {
					if strings.HasPrefix(p1.StaleReason, "stale dependency: ") {
						p.StaleReason = p1.StaleReason
						break
					}
					if strings.HasPrefix(p.StaleReason, "build ID mismatch") {
						p.StaleReason = "stale dependency: " + p1.ImportPath
					}
				}
			}
		}
	}

	// Begin saving output for later writing to cache.
	a.output = []byte{}
	return false
}

env PATH=''
env path=''

# Compiling the test should not require the VCS tool.
go test -c -o $devnull .


# When listing a main package, in general we need its VCS metadata to determine
# the .Stale and .StaleReason fields.
! go list -buildvcs=true .
stderr '^go: missing Git command\. See https://golang\.org/s/gogetcmd\nerror obtaining VCS status: .*\n\tUse -buildvcs=false to disable VCS stamping.'

        Standard       bool     // is this package part of the standard Go library?
        Stale          bool     // would 'go install' do anything for this package?
        StaleReason    string   // explanation for Stale==true
        Root           string   // Go root or Go path dir containing this package
        ConflictDir    string   // this directory shadows Dir in $GOPATH

			for _, p := range pkgs {
				if p.Name != "main" {
					continue
				}

				p.Target = filepath.Join(cfg.BuildO, p.DefaultExecName())
				p.Target += cfg.ExeSuffix
				p.Stale = true
				p.StaleReason = "build -o flag in use"
				a.Deps = append(a.Deps, b.AutoAction(ModeInstall, depMode, p))
			}
			if len(a.Deps) == 0 {
				base.Fatalf("go: no main packages to build")
			}
			b.Do(ctx, a)
			return

	// Stale and StaleReason remain here *only* for the list command.
	// They are only initialized in preparation for list execution.
	// The regular build determines staleness on the fly during action execution.
	Stale       bool   `json:",omitempty"` // would 'go install' do anything for this package?
	StaleReason string `json:",omitempty"` // why is Stale true?

	// Source files

	t.Run("newarchive", func(t *testing.T) {
		resetFileStamps()
		AssertNotRebuilt(t, "new .a file before build", target)
		goCmd(t, "list", "-linkshared", "-f={{.ImportPath}} {{.Stale}} {{.StaleReason}} {{.Target}}", "./depBase")
		AssertNotRebuilt(t, "new .a file before build", target)
		cleanup := touch(t, target)
		defer func() {
			cleanup()
			goCmd(t, "install", "-v", "-linkshared", "./exe")
		}()

	goCmd := []string{goBinary, "list"}
	if noOpt {
		goCmd = append(goCmd, "-tags=noopt")
	}
	goCmd = appendCompilerFlags(goCmd)
	goCmd = append(goCmd, "-f={{if .Stale}}\tSTALE {{.ImportPath}}: {{.StaleReason}}{{end}}")

	out := runEnv(workdir, CheckExit, env, append(goCmd, targets...)...)
	if strings.Contains(out, "\tSTALE ") {
		os.Setenv("GODEBUG", "gocachehash=1")

		}
	}
}

// isStale reports whether pkg is stale, and why
func (tg *testgoData) isStale(pkg string) (bool, string) {
	tg.t.Helper()
	tg.run("list", "-f", "{{.Stale}}:{{.StaleReason}}", pkg)
	v := strings.TrimSpace(tg.getStdout())
	f := strings.SplitN(v, ":", 2)
	if len(f) == 2 {
		switch f[0] {
		case "true":
			return true, f[1]
		case "false":
			return false, f[1]
		}

		// Don't try to build anything for packages with errors. There may be a
		// problem with the inputs that makes the package unsafe to build.
		return p.Error
	}

	if p.BinaryOnly {
		p.Stale = true
		p.StaleReason = "binary-only packages are no longer supported"
		if b.IsCmdList {
			return nil
		}
		return errors.New("binary-only packages are no longer supported")
	}

//	    Standard       bool     // is this package part of the standard Go library?
//	    Stale          bool     // would 'go install' do anything for this package?
//	    StaleReason    string   // explanation for Stale==true
//	    Root           string   // Go root or Go path dir containing this package
//	    ConflictDir    string   // this directory shadows Dir in $GOPATH