HPC-GAP/factint/travis interactions

[stevelinton]

Please use the following template to submit an issue
(you may delete lines which are not used). Thank You!

Observed behaviour

Travis tests fail for #2997. Specifically the HPCGAP test tst/testinstall/hpc/tasks.tst

The problem is seen in

gap> t := RunTask( Factors, Integers, 65537^2-1);
gap> TaskError(t);
"Error, Attempt to read object 4874949504 of type list (plain,empty) without having read access"

It can be avoided by running HPC-GAP with -A presumably because this suppresses factint

It seems that factint uses lots of caches and similar arrangements without any precautions for multi-threading.

Expected behaviour

This test should pass if the core system is correct.

I suggest not loading factint for HPC-GAP tests, since it is (a) used automatically by the library and (b) contains functions that cannot be run in a background thread.

[fingolfin]

A simple way to not load factint in the HPC-GAP test would be to edit etc/ci-prepare.sh and insert something like

if [[ $HPCGAP = yes ]]
then
  rm -rf $SRCDIR/pkg/FactInt*
fi

near or at the end.