cmd/go: don't crash when running "go version" in deleted directory

If the go command is executed on Linux in a deleted directory,
it fails. This behavior is reasonable for commands which depend on
the CWD, but it's unexpected for commands like `go version`.
This change delays initialization of a global CWD variable.

Fixed #34499

Change-Id: I7302fb84a3b7f5f149a123d277abd5b9b5bc95b2
Reviewed-on: https://go-review.googlesource.com/c/go/+/268261
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Trust: Bryan C. Mills <bcmills@google.com>
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>

1 files changed, 7 insertions, 7 deletions

diff --git a/src/cmd/go/internal/modload/init.go b/src/cmd/go/internal/modload/init.go
index 99c0c2b981..5cdea12cd3 100644
--- a/src/cmd/go/internal/modload/init.go
+++ b/src/cmd/go/internal/modload/init.go
@@ -135,7 +135,7 @@ func Init() {
 		return
 	}
 
-	if err := fsys.Init(base.Cwd); err != nil {
+	if err := fsys.Init(base.Cwd()); err != nil {
 		base.Fatalf("go: %v", err)
 	}
 
@@ -179,7 +179,7 @@ func Init() {
 		}
 		modRoot = ""
 	} else {
-		modRoot = findModuleRoot(base.Cwd)
+		modRoot = findModuleRoot(base.Cwd())
 		if modRoot == "" {
 			if cfg.ModFile != "" {
 				base.Fatalf("go: cannot find main module, but -modfile was set.\n\t-modfile cannot be used to set the module root directory.")
@@ -276,7 +276,7 @@ func WillBeEnabled() bool {
 		return false
 	}
 
-	if modRoot := findModuleRoot(base.Cwd); modRoot == "" {
+	if modRoot := findModuleRoot(base.Cwd()); modRoot == "" {
 		// GO111MODULE is 'auto', and we can't find a module root.
 		// Stay in GOPATH mode.
 		return false
@@ -335,8 +335,8 @@ func die() {
 	if cfg.Getenv("GO111MODULE") == "off" {
 		base.Fatalf("go: modules disabled by GO111MODULE=off; see 'go help modules'")
 	}
-	if dir, name := findAltConfig(base.Cwd); dir != "" {
-		rel, err := filepath.Rel(base.Cwd, dir)
+	if dir, name := findAltConfig(base.Cwd()); dir != "" {
+		rel, err := filepath.Rel(base.Cwd(), dir)
 		if err != nil {
 			rel = dir
 		}
@@ -479,7 +479,7 @@ func loadModFile(ctx context.Context) (rs *Requirements, needCommit bool) {
 // exactly the same as in the legacy configuration (for example, we can't get
 // packages at multiple versions from the same module).
 func CreateModFile(ctx context.Context, modPath string) {
-	modRoot = base.Cwd
+	modRoot = base.Cwd()
 	Init()
 	modFilePath := ModFilePath()
 	if _, err := fsys.Stat(modFilePath); err == nil {
@@ -646,7 +646,7 @@ func initTarget(m module.Version) {
 	Target = m
 	targetPrefix = m.Path
 
-	if rel := search.InDir(base.Cwd, cfg.GOROOTsrc); rel != "" {
+	if rel := search.InDir(base.Cwd(), cfg.GOROOTsrc); rel != "" {
 		targetInGorootSrc = true
 		if m.Path == "std" {
 			// The "std" module in GOROOT/src is the Go standard library. Unlike other