Hi, I have been setting up mail server on my guix machine and I have found a bug. The smtpctl command from the opensmptd package requires to be owned by the smtpq group. The problem is, that this group is added by opensmtp-service, but it is required during the build process as can be seen here http://ci.guix.gnu.org/build/748270/log/raw (search for chgrp) I write to you since I’m not sure how to fix it idiomatically. Here are my solutions: a) smtpq can be a system group that exists on all guix machines b) smtpq will get a static gid, the build process will create a dummy group with that gid, chgrp the file to that group and the opensmtp-service-type will create user-group smtpq with that static gid (i dont know if there’s an index of reserved guix gids) c) patch the upstream opensmtpd With all the best, Maya