Greetings, When I pass #f to spawn as a port, it just segfaults: $ guile -c '(spawn "true" (list "") #:error #f)' Segmentation fault Ignoring the fact whether #f should be an accepted value (I think it would be more elegant and portable then (open-output-file "/dev/null")), I would not expect invalid value in an interpreted language to cause a segfault. If the value is indeed invalid, it should throw an error. Original report: https://emacs.ch/@kakafarm/112075808549752692 Have a nice day, Tomas Volf -- There are only two hard things in Computer Science: cache invalidation, naming things and off-by-one errors.