diff -ru parallel-20110822/src/sem parallel-20110822.new/src/sem
--- parallel-20110822/src/sem	2011-08-21 16:17:43.000000000 -0700
+++ parallel-20110822.new/src/sem	2011-11-14 16:12:32.000000000 -0800
@@ -4743,6 +4743,7 @@
     chmod 0666, $self->{'lockfile'}; # assuming you want it a+rw
     $Global::use{"Fcntl"} ||= eval "use Fcntl qw(:DEFAULT :flock);";
     while(not flock $self->{'lockfh'}, LOCK_EX()|LOCK_NB()) {
+        if ($! =~ m/Function not implemented/) {die("flock: $!");}
 	::debug("Cannot lock $self->{'lockfile'}");
 	# TODO if timeout: last
 	$sleep = ($sleep < 1000) ? ($sleep * 1.1) : ($sleep);