cmd/compile: improve output when TestAssembly build fails

Change-Id: Ibee84399d81463d3e7d5319626bb0d6b60b86bd9
Reviewed-on: https://go-review.googlesource.com/40861
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/cmd/compile/internal/gc/asm_test.go b/src/cmd/compile/internal/gc/asm_test.go
index a36287865bcf8d6e45fedf1414c7010792b85785..e1b582dbf6d550a0eb1a1457113a8b57272c18d5 100644 (file)
--- a/src/cmd/compile/internal/gc/asm_test.go
+++ b/src/cmd/compile/internal/gc/asm_test.go
@@ -152,8 +152,7 @@ func (ats *asmTests) runGo(t *testing.T, args ...string) string {
        cmd.Stderr = &stderr
 
        if err := cmd.Run(); err != nil {
-               fmt.Printf(stdout.String())
-               t.Fatalf("error running cmd: %v", err)
+               t.Fatalf("error running cmd: %v\nstdout:\n%sstderr:\n%s\n", err, stdout.String(), stderr.String())
        }
 
        if s := stderr.String(); s != "" {