ginkgo run in parallel can hang when child command outlives test suite

[Luap99]

I have been debugging hangs in ginkgo v2 in over last weeks and I think I finally found the problem.
I created https://github.com/Luap99/ginkgo-hang for a simple reproducer.

This diff seems to fix the issue for me:

diff --git a/internal/output_interceptor_unix.go b/internal/output_interceptor_unix.go
index f5ae15b..70d5647 100644
--- a/internal/output_interceptor_unix.go
+++ b/internal/output_interceptor_unix.go
@@ -26,6 +26,11 @@ func (impl *dupSyscallOutputInterceptorImpl) CreateStdoutStderrClones() (*os.Fil
        stdoutCloneFD, _ := unix.Dup(1)
        stderrCloneFD, _ := unix.Dup(2)
 
+       flags, _ := unix.FcntlInt(uintptr(stdoutCloneFD), unix.F_GETFD, 0)
+       unix.FcntlInt(uintptr(stdoutCloneFD), unix.F_SETFD, flags|unix.FD_CLOEXEC)
+       flags, _ = unix.FcntlInt(uintptr(stderrCloneFD), unix.F_GETFD, 0)
+       unix.FcntlInt(uintptr(stderrCloneFD), unix.F_SETFD, flags|unix.FD_CLOEXEC)
+
        // And then wrap the clone file descriptors in files.
        // One benefit of this (that we don't use yet) is that we can actually write
        // to these files to emit output to the console even though we're intercepting output

By using CLOEXEC we make sure the fds are never leaked into commands that are executed in the test suite.
I am happy to open a PR if you agree that this is the right approach to fix the problem.

[onsi]

oh snap! this has been a loooong-standing issue and one i've spent a lot of effort trying to understand and fix. the best i've been able to do is provide a flag to disable output interception when this failure mode occurs. your description of the issue lines up with my understanding - i didn't know about CLOEXEC but it sounds like it resolves the root issue.

yes please do submit a PR!

[Luap99]

PR #1192