Re: Problems with GNU Parallel and ulimit

[Clément Lassieur]

Eric Bavier <address@hidden> writes:

> Sending response to the list this time...
>
>> Arun Isaac <address@hidden> writes:
>> 
>> > Leo Famulari writes:
>> >
>> >> On Mon, Aug 14, 2017 at 12:46:25PM +1000, Ben Woodcroft wrote:
>> >>> On 14/08/17 12:31, Arun Isaac wrote:
>> >>> > Does `parallel' work for anybody? When I run
>> >>> > 
>> >>> > $ ls | parallel echo
>> >>> > 
>> >>> > I get the following error message, and nothing happens.
>> >>> It works fine for me using Guix on a foreign OS, and has since I
>> >>> can remember.
>> >>> ben
>> >>
>> >> Same here. Arun, can you give some more details about your system?
>> >
>> > This is probably a problem only on GuixSD systems. Could you try on
>> > GuixSD instead of using Guix on a foreign distro?
>> 
>> I tested it on GuixSD, works fine. Are you trying the command in a
>> folder with > 1024 files perhaps? What does `ulimit -n` print?
>
> The problem appears if you do not have 'perl' available in $PATH. GNU
> parallel calls it recursively for a few tasks:
>
> $ guix package -I | grep "perl"
> $ echo $?
> 1
> $ parallel echo ::: 1 2 3
> ...
> 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 1.
> $ guix environment --ad-hoc perl
> [dev]$ parallel echo ::: 1 2 3
> 1
> 2
> 3
>
> There is some path patching that goes on in the package recipe, but it
> must have gone out of sync in latest versions.  The 'post-install-test'
> phase wouldn't catch this particular error without '(setenv "PATH" "")'.
>
> I wouldn't feel quite comfortable doing a "blind" update of the regex,
> since some mentions of "perl" I think are meant to be executed by
> remote hosts and so shouldn't be patched to absolute store references.

Hi,

This is fixed by 4e7950fdce5b83db018c44a80ec4a4059612d716 (it adds a
wrap-program phase).

Clément