Still failing. In ’compute-derivation’, this (s (list (package-source-derivation store s))))) returns a list of string instead of a derivation, so then (for-each show-derivation-outputs drv) fails because it expects a derivation or a derivation-input (see in(guix ui)). Well, I am not sure where the error should be handled. In (guix ui) andin (guix scripts build)? WDYT?