From 660feea72f64d9d6d619529f10afd8c042299c65 Mon Sep 17 00:00:00 2001
From: Cosmos Nicolaou <cosmos.nicolaou@gmail.com>
Date: Tue, 29 Aug 2023 14:34:40 -0700
Subject: [PATCH] runtime/pprof: print stderr on test failure

Print Stderr on test failure to track down the intermittent
test failure reported in issue #62352.

Change-Id: I547a3220dc07d05578dac093d6c028a9103b552a
Reviewed-on: https://go-review.googlesource.com/c/go/+/524156
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
---
 src/runtime/pprof/vminfo_darwin_test.go | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/runtime/pprof/vminfo_darwin_test.go b/src/runtime/pprof/vminfo_darwin_test.go
index c476110b09..b2b025668e 100644
--- a/src/runtime/pprof/vminfo_darwin_test.go
+++ b/src/runtime/pprof/vminfo_darwin_test.go
@@ -12,6 +12,7 @@ import (
 	"internal/abi"
 	"internal/testenv"
 	"os"
+	"os/exec"
 	"strconv"
 	"strings"
 	"testing"
@@ -54,9 +55,14 @@ func TestVMInfo(t *testing.T) {
 func useVMMap(t *testing.T) (hi, lo uint64) {
 	pid := strconv.Itoa(os.Getpid())
 	testenv.MustHaveExecPath(t, "vmmap")
-	out, err := testenv.Command(t, "vmmap", pid).Output()
+	cmd := testenv.Command(t, "vmmap", pid)
+	out, err := cmd.Output()
 	if err != nil {
-		t.Fatal(err)
+		t.Logf("vmmap failed: %s", out)
+		if ee, ok := err.(*exec.ExitError); ok && len(ee.Stderr) > 0 {
+			t.Fatalf("%v: %v\n%s", cmd, err, ee.Stderr)
+		}
+		t.Fatalf("%v: %v", cmd, err)
 	}
 	return parseVmmap(t, out)
 }
-- 
2.50.0