Looking at the code:

• https://github.com/wikimedia/labs-tools-wikibugs2/blob/master/wikibugs.py#L285 sets the transition information
• https://github.com/wikimedia/labs-tools-wikibugs2/blob/master/redis2irc.py#L101 adds the channel and matched projects
• https://github.com/wikimedia/labs-tools-wikibugs2/blob/master/messagebuilder.py#L179 adds the transition info to the message

Adding it as ping to the message may be non-trivial, as there is a risk of the message being truncated. In addition, the user would be pinged in each channel the change is reported. Maybe sending a privmsg is more practical?

I think the most practical implementation would be to add some logic after https://github.com/wikimedia/labs-tools-wikibugs2/blob/master/redis2irc.py#L101, calling a new config parser (along the lines of channelfilter.py) which determines which users to notify based on the projects & priority change.

As a first implementation, I would suggest making the configuration in Python, and basically making a component that takes useful_info and returns a list of usernames to send a private message to.

Maybe humans are better at determining who should be pinged for a specific issue than a script could be.

If humans are already doing that and then rsubscribe people to tickets then those people already get pinged by Phab notifications.

Then this might just be "translate phab names to IRC names using a table like on office wiki" and then a bot trigger to ping subscribers of a ticket given a ticket ID. This could happen automatically if UBN and be an optional manual trigger for any ticket.

Hmm, what's the advantage of IRC compared to e.g. a Herald rule to send an email to an email address like H329 or H315?

In T219573#5741799, @Aklapper wrote:

Hmm, what's the advantage of IRC compared to e.g. a Herald rule to send an email to an email address like H329 or H315?

No one (sanely) uses IRC for urgent issues. I get ~2000 e-mails a week from Phabricator. I don't respond immediately to getting e-mails there. I don't imagine many do.

True... To avoid potential misunderstanding / provide some more related info:

• You could tell the Herald rule to send UBN email notifications to a different email address, e.g. a team mailing list.
• For personal Phab email notifications, mw:Phabricator/Help/Managing_mail explains how you could filter Phab email notifications on the Priority field value (X-Phabricator-Mail-Stamps mail header being task-priority(100)) to treat them differently.