From 7aba72baaae64792707076724307f6bdc7fec44f Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Wed, 29 Feb 2012 15:53:57 -0500
Subject: [PATCH] os: diagnose chdir error during StartProcess

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5711044
---
 src/pkg/os/exec_posix.go | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/pkg/os/exec_posix.go b/src/pkg/os/exec_posix.go
index 4a75cb67fb..a686f44606 100644
--- a/src/pkg/os/exec_posix.go
+++ b/src/pkg/os/exec_posix.go
@@ -18,6 +18,16 @@ import (
 //
 // If there is an error, it will be of type *PathError.
 func StartProcess(name string, argv []string, attr *ProcAttr) (p *Process, err error) {
+	// Double-check existence of the directory we want
+	// to chdir into.  We can make the error clearer this way.
+	if attr != nil && attr.Dir != "" {
+		if _, err := Stat(attr.Dir); err != nil {
+			pe := err.(*PathError)
+			pe.Op = "chdir"
+			return nil, pe
+		}
+	}
+
 	sysattr := &syscall.ProcAttr{
 		Dir: attr.Dir,
 		Env: attr.Env,
-- 
2.50.0