It is currently impossible to post messages from a repo to a channel without also removing them from the default channel i.e. #wikimedia-dev.
(On the contrary, it's possible to send messages to multiple non-default channels. Hence, one could try regex magic and define the default channel explicitly by negation of all the repos it should not receive updates from, i.e. currently all the patterns in the config, but this is not desired.)
A new "nonexclusive-channels" list could be added for channels which want to receive updates from some repo(s) without removing them from the default channel.
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=55807