runtime: set GODEBUG=asyncpreemptoff=1 in TestCrashDumpsAllThreads

Fixes #35356

Change-Id: I67b9e57b88d00ed98cbc3aa0aeb26b5f2d75a3f7
Reviewed-on: https://go-review.googlesource.com/c/go/+/205720
Run-TryBot: Ian Lance Taylor <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Brad Fitzpatrick <[email protected]>
Reviewed-by: Cherry Zhang <[email protected]>

src/runtime/crash_unix_test.go

@@ -15,7 +15,6 @@ import (
  "os/exec"
  "path/filepath"
  "runtime"
- "strings"
  "sync"
  "syscall"
  "testing"
@@ -99,18 +98,17 @@ func TestCrashDumpsAllThreads(t *testing.T) {
 
  cmd = exec.Command(filepath.Join(dir, "a.exe"))
  cmd = testenv.CleanCmdEnv(cmd)
- cmd.Env = append(cmd.Env, "GOTRACEBACK=crash")
-
- // Set GOGC=off. Because of golang.org/issue/10958, the tight
- // loops in the test program are not preemptible. If GC kicks
- // in, it may lock up and prevent main from saying it's ready.
- newEnv := []string{}
- for _, s := range cmd.Env {
- if !strings.HasPrefix(s, "GOGC=") {
- newEnv = append(newEnv, s)
- }
- }
- cmd.Env = append(newEnv, "GOGC=off")
+ cmd.Env = append(cmd.Env,
+ "GOTRACEBACK=crash",
+ // Set GOGC=off. Because of golang.org/issue/10958, the tight
+ // loops in the test program are not preemptible. If GC kicks
+ // in, it may lock up and prevent main from saying it's ready.
+ "GOGC=off",
+ // Set GODEBUG=asyncpreemptoff=1. If a thread is preempted
+ // when it receives SIGQUIT, it won't show the expected
+ // stack trace. See issue 35356.
+ "GODEBUG=asyncpreemptoff=1",
+ )
 
  var outbuf bytes.Buffer
  cmd.Stdout = &outbuf