[t] Improve diagnostic messages in tests for mk_language_shell.t

git-svn-id: https://svn.parrot.org/parrot/trunk@49501 d31e2699-5ff4-0310-a27c-f18f2fbe73fe

t/tools/mk_language_shell.t

@@ -55,10 +55,16 @@ ok(-e $lang_dir, "$lang_dir dir exists");
 ok(-e $test_dir, "$test_dir dir exists");
 ok(-e $src_dir, "$src_dir dir exists");
 ok(-s $setup, "$setup exists and has nonzero size");
+
 my $build_status = system("cd $lang_dir; $parrot_exe setup.pir $to_dev_null");
-ok($? == 0, "language builds");
+my $build_error  = $!;
+diag("Faild to execute $parrot_exe setup.pir : $build_error") if $build_status == - 1;
+ok($build_status == 0, "language builds, exit code = " . ($build_status >> 8) );
+
 my $test_status = system("cd $lang_dir; $parrot_exe setup.pir test $to_dev_null");
-ok($? == 0, "language passes all tests");
+my $test_error  = $!;
+diag("Faild to execute $parrot_exe setup.pir test: $test_error") if $test_status == - 1;
+ok($test_status == 0, "language passes all tests, exit code = " . ($test_status >> 8) );
 
 =head1 HELPER SUBROUTINES