On Mon, Nov 05, 2018 at 09:39:15PM +0100, swedebugia wrote: > How do we catch the error? I am basically a novice Schemer still, so you will have to figure out most of this on your own, unless someone else brings more advice :) In general, dealing with exceptions in Guile: https://www.gnu.org/software/guile/manual/html_node/Exceptions.html There are lots of examples of how to use those mechanisms in the Guix source code — the error message in your original email comes from a caught exception in (guix build download). You'll need to find out what is crashing and generating the backtrace, and then decide what counts as a failure mode that we want to catch in that context.