Error computing H^1 over a module in char 0.

[fingolfin]

The following problem was reported by Yunus Emre Basar:

Consider this input:

LoadPackage("aclib");
G:=SpaceGroupPcpGroup(3,100);
N:=Center(G);
C:=CRRecordBySubgroup(G,N);;
OneCohomologyCR(C);

This leads to an error, in the code which deals with modules in characteristic 0:

gap> G:=SpaceGroupPcpGroup(3,100);
Pcp-group with orders [ 2, 2, 2, 0, 0, 0 ]
gap> N:=Center(G);
Pcp-group with orders [ 0 ]
gap> C:=CRRecordBySubgroup(G,N);;
gap> OneCohomologyCR(C);
Error, no method found! For debugging hints type ?Recovery from NoMethodFound
Error, no 1st choice method found for `TriangulizedIntegerMat' on 1 arguments at /Users/mhorn/Projekte/GAP/gap.github/lib/methsel2.g:250 called from
TriangulizedIntegerMat( sub ) at /Users/mhorn/Projekte/GAP/repos/pkg/pkg/pkg/polycyclic/gap/cohom/addgrp.gi:140 called from
AdditiveFactorPcp( cc, cb, C.char ) at /Users/mhorn/Projekte/GAP/repos/pkg/pkg/pkg/polycyclic/gap/cohom/onecohom.gi:71 called from
<function "OneCohomologyCR">( <arguments> )
 called from read-eval loop at *stdin*:13
you can 'quit;' to quit to outer loop, or
you can 'return;' to continue
brk>

Note that polycyclic does manage to compute a complement just fine:

gap> ComplementsCR(C);
[ Pcp-group with orders [ 2, 2, 2, 0, 0 ] ]
gap> Pcp(last[1]);
Pcp [ g1, g2, g3, g4, g5 ] with orders [ 2, 2, 2, 0, 0 ]
gap> Pcp(N);
Pcp [ g6 ] with orders [ 0 ]