ext/POISX/t/sigaction.t - failing under harness but not under test(and not failing with threads under harness)

Reduced the script to:

#!./perl

BEGIN {
         chdir 't' if -d 't';
         unshift @INC, '../lib';
}


use Test::More tests => 1;

use strict;


use POSIX qw(%SIGRT SIGRTMIN);
my $sigrtmin;
my $h = sub { $sigrtmin = 1 };
$SIGRT{SIGRTMIN} = $h;
kill 'SIGRTMIN', $$;
is($sigrtmin, 1, "SIGRTMIN handler works");


Running it (without threads):

./perl harness -v sigaction.t
sigaction....1..1
not ok 1 - SIGRTMIN handler works

#   Failed test 'SIGRTMIN handler works'
#   at sigaction.t line 19.
#          got: undef
#     expected: '1'
# Looks like you failed 1 test of 1.
dubious
         Test returned status 1 (wstat 256, 0x100)
DIED. FAILED test 1
         Failed 1/1 tests, 0.00% okay
Failed Test Stat Wstat Total Fail  List of Failed
-------------------------------------------------------------------------------
sigaction.t    1   256     1    1  1
Failed 1/1 test scripts. 1/1 subtests failed.
Files=1, Tests=1,  0 wallclock secs ( 0.11 cusr +  0.02 csys =  0.13 CPU)
Failed 1/1 test programs. 1/1 subtests failed.


./perl sigaction.t
1..1
ok 1 - SIGRTMIN handler works


Running it with -Duseithreads:

./perl harness -v sigaction.t
sigaction....1..1
ok 1 - SIGRTMIN handler works
ok
All tests successful.
Files=1, Tests=1,  0 wallclock secs ( 0.14 cusr +  0.03 csys =  0.17 CPU)


./perl sigaction.t
1..1
ok 1 - SIGRTMIN handler works



Can anyone offer some clues?

Kind regards,

Bram

• ext/POISX/t/sigaction.t - failing under harness but not under test(and not failing with threads under harness) by Bram