Top level, dif/2 odd answer, exception uncaught

[UWN]

l(X) :- dif(X,a),l(X).

?- l(X). % no reaction at all
?- catch(l(X), Pat,true).
ERROR: Stack limit (1.0Gb) exceeded % unexpected
...

9.1.5 `-f none` all defaults

[JanWielemaker]

Thanks. Should be fixed with SWI-Prolog/swipl-devel@8abc88e. Caused by running into another exception while trying to print the exception because the logic to do the last emergency stack shift was broken. Pushed an additional commit that tries simple printing if print_message/2 runs into an exception, so at least something is printed.