Creating test cases seems to loop forever when grammar doesn't use fields (by accident)

[inariksit]

Writing this down, on the off chance that I/someone would some day work on gftest again.

I was splitting a CN into two fields, like this

-- old
lincat CN = {s : Str} ;
lin AdvCN adv cn = {s = cn.s ++ adv.s} ;

-- new
lincat CN = {s, postmod : Str} ;
lin AdvCN adv cn = cn ** {postmod = cn.postmod ++ adv.s} ;

Then I had a bunch of functions that used the CN, like this

lin UseCNSomeWay cn stuff = stuff ** {s = stuff.s ++ cn.s} ;

But now that CN had two fields, whatever is in the postmod field never got propagated further. When I ran gftest on this grammar, it seemed to loop forever trying to make test cases. When I fixed my error, i.e. did like this

lin UseCNSomeWay cn stuff = stuff ** {s = stuff.s ++ cn.s ++ cn.postmod} ;

gftest was generating test cases again.