When testing in parallel, orphaned grandchild pids cause problems with Test2.

[mvsjes2]

When running tests in parallel, if one of the test classes also creates forks, and any of those 'grandchild' forks dies, it can mess up Test2::ASync and possibly cause other follow-on problems duing global destruction.

To recreate:

Create a parent script to run tests:

use Test::Class::Moose::Load './t';
use Test::Class::Moose::Runner;
my $runner = Test::Class::Moose::Runner->new(jobs => 3);
$runner->runtests;

...and a child class in a 't' subfolder that is set up to die:

package Class1;

use Test::Class::Moose;
use Parallel::ForkManager;

sub test_process {
    my $pm = Parallel::ForkManager->new(1);
    if (!$pm->start) {
        pass;
        die 'grand child object died';
        $pm->finish;
    }
    $pm->wait_all_children;
}

1;

Produces "Attempt to detach from wrong child" from Test2::Async while the test suite is running, and "Subtest can only be finished in the process/thread that created it" during destruction.