Merging https://gerrit.wikimedia.org/r/#/c/238426/ failed on a superfluous entry in qqq.json, because a key was removed from en.json. This shouldn't happen. Superfluous entries in qqq.json are of no concern.
No idea which project this should be reported in, but I tried Jenkins, and added Antoine as CC.
@Mattflaschen mentioned on the Gerrit change:
Patch Set 6:
It's deliberate. It avoids the problem of a non-existent message lingering in qqq for whatever reason (maybe a developer intended to add a message, so documented it, but decided they didn't need it).
This has been documented for a while at https://www.mediawiki.org/wiki/Localisation#Removing_existing_messages .
Seems it is working as intended. If it is a concern / unwanted behavior, you will want to fill an issue on the banana checker issue tracker which annoyingly is on GitHub: https://github.com/wikimedia/grunt-banana-checker/issues