I guess that it was 5c3de992f4d0e540180aef7514eb374a7b8b80ea (Change-Id: Id506e52a93e4ed2524abd7073fc024f57096fc64) that is responsible. Adding @Paladox as the author. Can you have a look? This is obviously affecting dumps running right now.

Change 275900 had a related patch set uploaded (by ArielGlenn):
Revert "Fix php5.5 errors"

https://gerrit.wikimedia.org/r/275900

Oh sorry I broke it. I'm not sure how to fix it for php 5.5 then. It fails the builds.

Hi we're you running php 5.5 or php 5.3. If it was php 5.3 then it may cause problems.

php 5.5 on all snapshots, trusty.

Change 275900 abandoned by Catrope:
Revert "Fix php5.5 errors"

Reason:
Doesn't seem to revert the right commit, since the issue is present in wmf15 too.

https://gerrit.wikimedia.org/r/275900

Oh thanks for replying. I'm not sure why it broke.

Could you try the latest of the master branch since wmf16 has been cut.

Yes, it's going to take a minute because I"ll have to run the updates, but I think I can get that set up for local testing (not live testing).

I can verify that wmf15 is failing and that the above change isn't in there. (But it looked like exactly the right candidate. My apologies.) Going hunting now.

I'm still updating my very ancient local MW install so I can run tests.
"Updating *_from_namespace fields in links tables."

While I wait,
6e9b4f0e9ce4ccd6089c18b205065ef7fa077484 (I2c8ce713ce6600a0bb7bf67537c87044c7a45c4b) and
415953d91e1acbddace8b761b218cf2f78d6a974 (I3bd8e7c4d2dca465957a353cb7dc2a906699ff6a)
are the two other candidates I see that might have done us in.

This https://phabricator.wikimedia.org/rMW6e9b4f0e9ce4ccd6089c18b205065ef7fa077484 is unlikely since it converts arrays to []. This also https://phabricator.wikimedia.org/rMW415953d91e1acbddace8b761b218cf2f78d6a974 since php 5.5 breaks on for example &$the.

and yet https://phabricator.wikimedia.org/rMW415953d91e1acbddace8b761b218cf2f78d6a974 was the one. I just checked by applying this:

$ diff /srv/mediawiki/php-1.27.0-wmf.15/maintenance/backup.inc.saveme /srv/mediawiki/php-1.27.0-wmf.15/maintenance/backup.inc.works
141c141

< call_user_func_array( $register, [ $this ] );

		call_user_func_array( $register, [ &$this ] );

Because your changeset in wmf16 hasn't gone yet, I'm guessing. Anyways with that fix (rolling back effectively the 4159 change), it works, without it I get:

Warning: Parameter 1 to AbstractFilter::register() expected to be a reference, value given in /srv/mediawiki/php-1.27.0-wmf.15/maintenance/backup.inc on line 141
Unrecognized filter type 'abstract'

Roan tells me wmf16 will go tomorrow, first to non wps, so I'll be checking those and if they look good then we're done. If not, ... I'll Be Back. Keeping this open for now.

After wmf16 deployment on group 1 I am still waiting for an abstracts job to fire on a non-wikipedia or, alternatively, for group 2 to go tonight. In the meantime, no new news.