Tweak GNU parallel arguments

[holtgrewe]

Sometimes GNU parallel fails because multiple hosts touch the same file in $HOME:

parallel: This should not happen. You have found a bug. Please follow
https://www.gnu.org/software/parallel/man.html#reporting-bugs

Include this in the report:
* The version number: 20221122
* The bugid: Cannot read /data/gpfs-1/users/holtgrem_c/.parallel/tmp/sshlogin/hpc-cpu-144/linelen
* The command line being run
* The files being read (put the files on a webserver if they are big)

We should rather use a custom --workdir and --plain.

For example:

mkdir -p $TMPDIR/parallel
cat $TMPDIR/final_intervals.txt \
| parallel --workdir $TMPDIR/parallel --plain -j $num_threads 'run-shard {{#}} {{}}'

[holtgrewe]

We probably need to

• report the bug
• put a random sleep before the invocation

[holtgrewe]

https://serverfault.com/questions/347582/adding-a-random-delay-for-a-linux-command