My system recently broke when I did an upgrade. I reported what I thought was a bug (bug#29072) but it turned out that, because qemu package code had been moved, my system configuration had become broken ;-( Confronted with my situation, helpful developers said "The package code was moved in commit xxx" (Leo) and "maybe you have a mistake in your config (Efraim)." Once I understood what had happened I wondered, "Gee, I have been using guix for 18 months so why didn't I figure this out myself." ;-) But a less committed user might say, "Wow, Guix breaks at random, error messages are hard to understand, and support is difficult." :-( ISTM this raises issues and questions about Guix configuration usability: Guix config errors are reported as raw scheme errors which are not user-friendly, except, perhaps, to guile users ;-) Could we improve this situation by adding config troubleshooting guidance to the doc? Guix config errors consume meaningful amounts of user and support effort. I say this because a) it took quite a few iterations to figure out what was wrong in my situation, and b) google search for '"no code for module" guix' finds 613 hits, which will no doubt grow linearly with number of Guix users unless something is done. So I wonder, could an error handler that translates into more user-friendly terms reduce user frustration, increase the rate of user self help, reduce support load, and effectively pay for itself? Are the current Guix config errors usable by the average GNU/Linux distribution user? If not, don't they need to be improved before we call it 1.0? Does this mean that package code must not be moved after 1.0? Finally: Should I close bug#29072? ;-)