reset() expects parameter 1 to be array, null given
Stack trace:
# PhutilErrorHandler::handleError called at [arcanist/src/error/PhutilErrorHandler.php:261]
# reset called at [phabricator/src/applications/diffusion/query/DiffusionRenameHistoryQuery.php:100]
# DiffusionRenameHistoryQuery::loadCommitSequence called at [phabricator/src/applications/diffusion/query/DiffusionRenameHistoryQuery.php:45]
# DiffusionRenameHistoryQuery::loadOldFilename called at [phabricator/src/applications/diffusion/controller/DiffusionBrowseController.php:654]
# DiffusionBrowseController::buildBeforeResponse called at [phabricator/src/applications/diffusion/controller/DiffusionBrowseController.php:110]
# DiffusionBrowseController::browseFile called at [phabricator/src/applications/diffusion/controller/DiffusionBrowseController.php:48]
# DiffusionBrowseController::handleRequest called at [phabricator/src/aphront/configuration/AphrontApplicationConfiguration.php:284]

This is literally https://secure.phabricator.com/T13667#256672 in old upstream.

I see no recent changes to source code files (1, 2) so I assume this is still an issue.

Looking at the code in DiffusionRenameHistoryQuery.php:89, I assume SELECT commitSequence FROM phabricator_repository.repository_pathchange WHERE (repositoryID = "PHID-REPO-5qissrjui3b35nz2mmif" OR repositoryID = 989) AND commitID = "14476579ffccb1238c81aeb47442c74677c06ee2"; is null. (Cannot check as I don't have DB permissions.)

Indeed, SELECT commitSequence FROM phabricator_repository.repository_pathchange WHERE commitID = "14476579ffccb1238c81aeb47442c74677c06ee2"; has zero results in the DB

This makes no sense, as commitIDs are integer only. I need to check the code more thoroughly.

This does not happen on current https://phabricator.wikimedia.org/source/mediawiki-config/browse/master/wmf-config/CommonSettings.php

We are looking at the URI https://phabricator.wikimedia.org/source/mediawiki-config/browse/master/wmf-config/CommonSettings.php;14aaa8d1fa8401ddb52f7e248bdc816fa1a2aa91?before=14476579ffccb1238c81aeb47442c74677c06ee2
which includes the two Commit IDs:

• 14476579ffccb1238c81aeb47442c74677c06ee2 (before)
• 14aaa8d1fa8401ddb52f7e248bdc816fa1a2aa91 (current)

mysql:phstats@m3-slave.eqiad.wmnet [phabricator_repository]> SELECT pc.commitSequence FROM phabricator_repository.repository_pathchange pc INNER JOIN phabricator_repository.repository_commit co ON pc.commitID = co.id WHERE pc.repositoryID = 989 AND co.commitIdentifier = "14476579ffccb1238c81aeb47442c74677c06ee2" LIMIT 1;
does create output (actually three entries).

mysql:phstats@m3-slave.eqiad.wmnet [phabricator_repository]> SELECT pc.commitSequence FROM phabricator_repository.repository_pathchange pc INNER JOIN phabricator_repository.repository_commit co ON pc.commitID = co.id WHERE pc.repositoryID = 989 AND co.commitIdentifier = "14aaa8d1fa8401ddb52f7e248bdc816fa1a2aa91" LIMIT 1;
does not create output: Empty set.

Because https://phabricator.wikimedia.org/rOMWC14aaa8d1fa8401ddb52f7e248bdc816fa1a2aa91 says Still Importing... This commit is still importing. Changes will be visible once the import finishes.

I think that's the culprit.

In a local git checkout, that commit renders correctly via [mediawiki-config]$ git show 14aaa8d1fa8401ddb52f7e248bdc816fa1a2aa91

We also see that "Still Importing..." also in a bunch of other commits, e.g. https://phabricator.wikimedia.org/rOPUP1005598170c55c3a47f02ea72328435415a8d30f

Question is how to see/find the corresponding daemon task ID, and a log which provides pointers about the underlying issue.
grep -r "Error while executing Task" /var/log/phd/daemons.log provides no results.
https://phabricator.wikimedia.org/daemon/ shows nothing stuck.
cf https://we.phorge.it/Q55

May want to finish cleanup in T362021 first anyway.

After running ./bin/repository reparse --importing --trace rOMWC14aaa8d1fa8401ddb52f7e248bdc816fa1a2aa91 I cannot reproduce this issue anymore.

So indeed this exception is directly linked to stuck imports of commits. Code could probably made more robust...