[GAP Forum] Problem with ParGap and ParList

[Mark Flanagan]

Hello everyone,

Hopefully issues with ParGap are on-topic for the GAP forum.

Running ParGap with open mpi. ParList works with a simple function
loaded into ParGap with ParRead, eg ParList([1..10],testfunc) when

testfunc:= function(x) return x+x; end;;

is used, but in more complicated use cases,
ParList(producehoms(3),loopofhom) does not work:

gap> ParList(producehoms(3),loopofhom);
Error, Variable: 'f1' must have a value
Error, List Assignment: <rhss> must be a list with the same length as
<positions> (14\
) in
  result{range} := tmp; called from
<function "ParList">( <arguments> )
 called from read-eval loop at line 3 of *stdin*
you can replace <rhss> via 'return <rhss>;'
brk> Error, Variable: 'f1' must have a value

producehoms(3) makes a list of homomorphisms and loopofhom is a
function, and  f1 is a generator of a group loaded in with ParRead.
List(producehoms(3),loopofhom) works as expected on master, and it
seems like ParRead worked because

SendRecvMsg("List(producehoms(3),loopofhom)",1);

produces the expected output.

Any thoughts on why ParList isn't working right? Would it just be
easier to parallelize my code manually, rather than relying on
ParList? Any advice is appreciated.

Mark