GNU Parallel Bug Reports GNU Parallel fails if 'perl' not in $PATH

[Eric Bavier]

Good Day,

I am reporting that GNU Parallel fails if a 'perl' program is not
available in $PATH.

With the GNU Guix package manager, if a user installs a programs which
is an interpreted script, they are not forced to also install into
their profile that program's interpreter.

GNU Parallel recursively invokes the 'perl' program in various places,
which fails for the stated reason.  E.g. in guix we can install
parallel into a one-off environment:

$ guix environment --ad-hoc parallel
[dev]$ parallel echo {} ::: a b c
parallel: Warning: No more processes: Decreasing number of running jobs to 2.
parallel: Warning: Raising ulimit -u or /etc/security/limits.conf may help.
parallel: Warning: No more processes: Decreasing number of running jobs to 1.
parallel: Warning: Raising ulimit -u or /etc/security/limits.conf may help.
parallel: Error: No more processes: cannot run a single job. Something is wrong 
at a.
[dev]$ ^D

But if we also add the perl package to the environment, parallel
works as expected:

$ guix environment --ad-hoc parallel perl
[dev]$ parallel echo {} ::: a b c
a
b
c
[dev]$ ^D

I tried at one point replacing references to 'perl' with '$^X', which
seemed to fix at least this trivial case (I unfortunately have since
lost the modified code, so no patch :(

Do you think you could consider fixing this?

Thanks,
`~Eric