Unmergeable merge request due to failing git hook

I tried to merge this simple MR for nearly a day: GNOME/totem!74 (merged) to no avail. Clicking the "merge immediately" button would show a spinner that never stopped.

Trying to merge it by hand would show why:

$ git push
Enumerating objects: 19, done.
Counting objects: 100% (19/19), done.
Delta compression using up to 4 threads
Compressing objects: 100% (10/10), done.
Writing objects: 100% (10/10), 1005 bytes | 1005.00 KiB/s, done.
Total 10 (delta 9), reused 0 (delta 0)
remote: ---
remote: ERROR: totem.doap is not valid:
remote:    description property is required and should be a string literal
remote: 
remote: Please see:
remote:    https://wiki.gnome.org/Git/FAQ
remote: ---
To gitlab.gnome.org:GNOME/totem.git
 ! [remote rejected]     master -> master (pre-receive hook declined)
error: failed to push some refs to 'git@gitlab.gnome.org:GNOME/totem.git'

It would be great if there was a project-level CI automatically applied to merge requests that would run it through the same checker that commits to master do, so that errors show somewhere on the GitLab UI.