On 08/11/17 15:45, Manuel Eberl wrote: > Is there an easy way to disable that for testing purposes? Some line I > have to remove from a .scala file or something? It should be sufficient to remove the is_pure() here: http://isabelle.in.tum.de/repos/isabelle/annotate/3ff88fece1f6/src/Pure/Tools/build.scala#l522 Makarius