singleton for script with shebang

[Bradley Asztalos]

I have a simple script, foo.sh::

#!/bin/bash
echo "start" $$
sleep 10
echo "end" $$

I can run make sure this runs as a singleton with

sem --fg -u --id lock_id ./foo.sh

But I'm wondering if it is possible to use shebang in this context as in:

-------singleton.sh---------

#!/opt/local/bin/parallel --shebang-wrap /bin/bash --semaphore --fg -u --id
lock_id
echo "start" $$
sleep 10
echo "end" $$

---------

This does not work. Any ideas here?

Bradley