300920 2025-10-16 13:22:16 -0700 [build.webkit.org] Build requests are not collapsed since the switch to multi-master mode 2026-03-10 08:28:02 -0700 1 1 1 Unclassified WebKit Tools / Tests WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED https://bugs.webkit.org/show_bug.cgi?id=300713 https://bugs.webkit.org/show_bug.cgi?id=302874 InRadar P2 Normal --- 1 clopez clopez webkit-bug-importer oldest_to_newest 2151780 0 clopez 2025-10-16 13:22:16 -0700 At 301496@main I thought that the issue with build requests not being collapsed on build.webkit.org since the migration to 4.3.0 was due to the change of default value for the parameter collapseRequests from 2.10 to 4.3.0, but this was not the case in the end. The problem was not because of the upgrade of version, but because of the multi-master deployment that was done when the version was upgraded. The core issue happens here: https://github.com/buildbot/buildbot/blob/6786251177836ab01b88d029aaa5821016976970/master/buildbot/process/buildrequest.py#L72 @defer.inlineCallbacks def collapse(self): brids_to_collapse = set() for brid in self.brids: # Get the BuildRequest object br = yield self.master.data.get(('buildrequests', brid)) # <- It gets all the info fine from the buildrequest (this is a query to the DB) # Retrieve the buildername builderid = br['builderid'] bldrdict = yield self.master.data.get(('builders', builderid)) # <- It gets all the info fine from the builder (this is a query to the DB) # Get the builder object bldr = self.master.botmaster.builders.get(bldrdict['name']) # <- Returns None, here it is where it fails! if not bldr: continue bldrdict['name'] gets resolved correctly to the name of the builder, but self.master.botmaster.builders is an empty dictionary on the -webserver master That is because this code to collapse the build-requests run on the master -webserver , and there are no builders defined on it, so there are no "builder object" available The data is coherent, the -webserver master is able to access all the builder information from the DB but it fails when tries to retrieve the python object that represent such builder, which obviously can't get that from the DB. So the easy way to fix this without patching buildbot code is that we define the workers and the builders also on the -webserver master, that way it can find the builder object and continue executing the collapse function as expected. 2151792 1 clopez 2025-10-16 13:48:00 -0700 Pull request: https://github.com/WebKit/WebKit/pull/52506 2151800 2 ews-feeder 2025-10-16 13:54:32 -0700 Committed 301655@main (c9fec4eec9b7): <https://commits.webkit.org/301655@main> Reviewed commits have been landed. Closing PR #52506 and removing active labels. 2151801 3 webkit-bug-importer 2025-10-16 13:55:11 -0700 <rdar://problem/162804817> 2188686 4 clopez 2026-03-10 08:28:02 -0700 Note: a fix for this was merged in buildbot at https://github.com/buildbot/buildbot/commit/878c45da92fa237b4e0178a5af0c4334119900f5 via https://github.com/buildbot/buildbot/pull/8705 If the next master upgrade includes that fix I guess we can go back to not define the workers on the Web UI master.