The problem is in the packages loaded (or not) by Sage's GAP vs by GAP's GAP. Namely, if I start Sage's gap by ./sage --gap and do gap> LoadAllPackages(); gap> NormalSubgroups(SmallGroup(1458,1180)); I'd get your error
Now, if I take GAP's source for 4.8.6: https://www.gap-system.org/pub/gap/gap48/tar.bz2/gap4r8p6_2016_11_12-14_25.tar.bz2 untar it, and copy its pkg/ directory to $SAGEROOT/local/gap/latest/ start Sage's gap by ./sage --gap and do gap> LoadAllPackages(); gap> NormalSubgroups(SmallGroup(1458,1180)); [ <pc group of size 1458 with 7 generators>, Group([ f1, f2, f3^2*f4, f5, f6, f7 ]), Group([ f2, f3^2*f4, f4, f5, f6, f7 ]), Group([ f1, f3^2*f4, f4, f5, f6, f7 ]), Group([ f1, f2*f4*f6, f3^2*f4, f5, f6, f7 ]), Group([ f1, f2^2*f4*f6^2, f3^2*f4, f5, f6, f7 ]), Group([ f1, f3^2*f4, f5, f6, f7 ]), Group([ f3^2*f4, f4, f5, f6, f7 ]), Group([ f2*f4*f6, f3^2*f4, f5, f6, f7 ]), Group([ f2^2*f4*f6^2, f3^2*f4, f5, f6, f7 ]), Group([ f2, f3^2*f4, f5, f6, f7 ]), Group([ f1, f3^2*f4, f5*f6^2, f7 ]), Group([ f3^2*f4, f5, f6, f7 ]), Group([ f2*f3^2*f4, f3^2*f4^2, f5*f6^2, f6, f7 ]), Group([ f3^2*f4^2, f5*f6^2, f6, f7 ]), Group([ f2*f3*f6*f7, f5*f6^2, f6, f7 ]), Group([ f2^2*f4*f6^2, f5*f6^2, f6, f7 ]), Group([ f2*f3^2*f4, f5*f6^2, f6, f7 ]), Group([ f5*f6^2, f6, f7 ]), Group([ f3^2*f4, f5*f6^2, f7 ]), Group([ f3^2*f4^2, f5^2*f6^2, f7 ]), Group([ f5^2*f6^2, f7 ]), Group([ f5*f6^2, f7 ]), Group([ f7 ]), Group([ ]) ] --- it works. Note that LoadAllPackages() is necessary, as apparently the GAP code uses one of these packages for these computation without telling us. So this is a sort of bug, yes, in our way of packaging GAP packages (and it's a sort of GAP's bug to call a code from a package without loading it explicitly...) I don't know what package it is yet. It's very early Sat. morning here, I'll have a look at it over the weekend. On Saturday, February 17, 2018 at 3:12:25 AM UTC, David Roe wrote: > > I'm trying to use GAP's small groups library (after installing > gap_packages) and getting strange errors that don't occur in GAP when built > from source. In particular (using gap_console to get more traceback) > > sage: gap_console() > ... > gap> NormalSubgroups(SmallGroup(1458,1180)); > Error, List Element: <list>[4] must have an assigned value in > if map[d] > max then > elm := id; > else > if not IsBound( map[d] ) then > Error( "<elm> lies not in group defined by <pcgs>" ); > fi; > ll := LeadingExponentOfPcElement( pa, elm ); > lr := lc[d]; > exp[map[d]] := ll / lr mod ros[d]; > elm := LeftQuotientPowerPcgsElement( pcgs, map[d], exp[map[d]], elm ); > fi; at /home/roed/sage/local/gap/latest/lib/pcgsind.gi:1411 called from > ExponentsOfPcElement( NumeratorOfModuloPcgs( pcgs ), elm, pcgs!.depthMap ) > at /home/roed/sage/local/gap/latest/lib/pcgsmodu.gi:931 called from > ExponentsOfPcElement( ocr.modulePcgs, x ) at > /home/roed/sage/local/gap/latest/lib/onecohom.gi:264 called from > ocr.moduleMap( n ) at /home/roed/sage/local/gap/latest/lib/onecohom.gi:339 > called from > ocr.listToCocycle( lc ) at /home/roed/sage/local/gap/latest/lib/ > grplatt.gi:1926 called from > opr( Zero( vs ), k ) at /home/roed/sage/local/gap/latest/lib/ > grplatt.gi:1932 called from > ... at line 2 of *stdin* > > Similar problems are occurring with other groups and some other functions. > > In the interest of finishing my calculation, I tried the following in an > attempt to have Sage use a functional GAP: > > sage: import sage.interfaces.gap > sage: sage.interfaces.gap.gap_cmd = "/home/roed/gap4r8/bin/gap.sh" > sage: gap.eval('1+1') > > which hangs. Similarly, I tried copying my functional gap installation to > $SAGE_LOCAL/gap/ and updating the "latest" symlink; this allows > gap_console() to function correctly but gap.eval() still hangs. > > I don't tend to work with spkgs very often, so I feel like there's > probably something simple I'm overlooking. Any help in installing a > functioning gap would be appreciated. I'm also happy to help investigate > what's wrong with our process for installing the small groups library. > David > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
