src/cmd/cgo/util.go | 4 ++--

diff --git a/src/cmd/cgo/util.go b/src/cmd/cgo/util.go
index 921306b7aabf653c5d60c04aaee505c8d86bb75d..779f7be2259b3750166b6edce318adb779e7a3a6 100644
--- a/src/cmd/cgo/util.go
+++ b/src/cmd/cgo/util.go
@@ -63,7 +63,7 @@ 	// Disable escape codes in clang error messages.
 	p.Env = append(os.Environ(), "TERM=dumb")
 	err := p.Run()
 	if _, ok := err.(*exec.ExitError); err != nil && !ok {
-		fatalf("%s", err)
+		fatalf("exec %s: %s", argv[0], err)
 	}
 	ok = p.ProcessState.Success()
 	stdout, stderr = bout.Bytes(), berr.Bytes()
@@ -88,7 +88,7 @@ func fatalf(msg string, args ...interface{}) {
 	// If we've already printed other errors, they might have
 	// caused the fatal condition. Assume they're enough.
 	if nerrors == 0 {
-		fmt.Fprintf(os.Stderr, msg+"\n", args...)
+		fmt.Fprintf(os.Stderr, "cgo: "+msg+"\n", args...)
 	}
 	os.Exit(2)
 }