Currently, Formaline doesn't find a globally installed simfactory. The build succeeds, but produces error messages close to the end like
sh: 1: /home/knarf/Cactus/bin/sim: not found
The attached patch tries, after not finding 'sim' in that location simply 'sim' - to be searched for in the users' search path. It also redirects stderr of the first (but not second) try to /dev/null to avoid these error messages. It doesn't do this for the second try to make sure the users sees 'something' which points towards Formaline not finding something.