$force_var = 'PERL_FORCE_TEST_THREADS' unless defined $force_var;
my $force = $ENV{$force_var} ? 1 : !1;
skip_all 'perl 5.13.4 required to test thread safety'
$force_var = 'PERL_FORCE_TEST_THREADS' unless defined $force_var;
my $force = $ENV{$force_var} ? 1 : !1;
skip_all 'perl 5.13.4 required to test thread safety'