38502 2010-05-03 18:40:12 -0700 [Qt] Qt build system failed to notice dependency changes after r58712 2012-02-02 10:26:22 -0800 1 1 1 Unclassified WebKit WebCore Misc. 528+ (Nightly build) Other Linux RESOLVED FIXED LayoutTestFailure, Qt, QtTriaged P2 Normal --- 1 dimich webkit-unassigned barraclough benjamin eric ossy oldest_to_newest 220410 0 dimich 2010-05-03 18:40:12 -0700 http://build.webkit.org/builders/Qt%20Linux%20Release/builds/11163 http://build.webkit.org/builders/Qt%20Linux%20Release/builds/11168 http://build.webkit.org/builders/Qt%20Linux%20Release/builds/11169 It started happening with r58712 although it's possible this change shifted timing enough for some existing race to get worse. Unfortunately, it seems the release Qt builds do not have symbols. 220426 1 eric 2010-05-03 19:49:00 -0700 Either way, we can't leave this crashing. We need to revert the revert or skip the test or fix whatever is causing this. We can't just leave the tree red. 220440 2 barraclough 2010-05-03 20:47:40 -0700 I believe that Ossy reported that this was caused by the QT build script failing to detect a dependency change after the update pulled in r58712, and that a clean build fixed the problem for him in his local build. Did I misunderstand something, or did that turn out not to be the case? Does this just require a nice clean build on the bot?, or is there another problem? 220443 3 eric 2010-05-03 20:57:18 -0700 You're right, this has resolved itself. So I guess we should change this bug to be a bug in the Qt build system then. Do we know what about the dependencies the build script failed to notice? 220444 4 eric 2010-05-03 20:57:57 -0700 Thank you both for your prompt followup. 220445 5 eric 2010-05-03 21:00:02 -0700 I always hit the security checkbox by accident. :( 220472 6 barraclough 2010-05-03 22:15:45 -0700 (In reply to comment #3) > Do we know what about the > dependencies the build script failed to notice? I believe Ossy thought he understood this, he explained to me on irc something like: (1) The revert removed wtf/text/AtomicStringTable.h (2) ... (3) This causing some .o's to not get rebuilt. I'm afraid I didn't really follow step 2 myself, but Ossy seemed to see what was going on. :o) As a workaround I suggested we could make the QT bot spot files being removed in an update & force a rebuild. Ossy appeared to think this might work, but was going to try to fix the dependencies in the makefile properly first, before resorting to hackery. :-) 220536 7 ossy 2010-05-04 02:47:57 -0700 r58712 made fast/workers/worker-gc2.html crash. I played a lot with this bug. If I skipped fast/workers/worker-gc2.html, fast/workers/worker-gc.html crashed. And I had a suspicion, I thought it is a DRT sideeffect. After skipped the test before fast/workers/worker-gc.html, I didn't get any crash. (with run-webkit-tests fast/workers --iterations 100) So I skipped fast/workers/worker-event-listener.html until fix: http://trac.webkit.org/changeset/58746 The other potential problem, dependency feature is unrelated to this crash, but I'm going to examine it too. 220659 8 dimich 2010-05-04 10:47:09 -0700 Yep, unfortunately, this wasn't the issue of clean build and we still have a failure here, Ossy had to disable a test to green the tree. Here is a sequence of events: The first this crashed after r58712 even though suspicion is that change only changed timing to expose existing issue: http://build.webkit.org/builders/Qt%20Linux%20Release/builds/11158 Ossy triggered clean build on the bot, which helped, lathough temporarily (perhaps shifting : http://build.webkit.org/builders/Qt%20Linux%20Release/builds/11164 After some more builds (and perhaps a bit of change in timing again) the crash re-appeared: http://build.webkit.org/builders/Qt%20Linux%20Release/builds/11181 Ossy finds out the test fails because of the sideeffect of the preceeding worker-event-listener.html and disables that on Qt, bot goes green again: http://build.webkit.org/builders/Qt%20Linux%20Release/builds/11194 220671 9 dimich 2010-05-04 11:08:37 -0700 Discussed with Ossy, we need to split this issue in 2 - about failing test and dependency issue in build system. More details on dependency issue, compiled from IRC chat: When you remove a file from the tree, it will be removed from the makefiles, dependencies, etc. But if you remove the dependency, it might be some trash in an object, lib. Try to imagine a foo.so : a.o b.o c.o rule, and if you remove a.c from the tree, the new rule will be foo.so : b.o c.o , without a.o. This rule won't trigger a new linking. 221250 10 barraclough 2010-05-05 13:20:32 -0700 Okay, I think I've figured out the worker-gc2 crash, and I think it's related to a change I made a few weeks ago. The bug was in existence prior to r58114. This introduced leaks, which will have masked the bug (the bug is a use after release of the objects leaked by r58114). r58712 then appeared to break the test, since it stopped leaking these objects again, making the bug possible. The bug is currently only biting on QT since it is platform dependent – it depends on the ordering that ThreadSpecifics are deleted, which is not defined. patch incoming. 221255 11 barraclough 2010-05-05 13:30:46 -0700 Actually, I shouldn't steal this bug – is there still an issue to resolve re the build system's dependencies Ossy? new bug: https://bugs.webkit.org/show_bug.cgi?id=38604 221411 12 barraclough 2010-05-05 18:14:10 -0700 bug #38604 is fixed in r58851, hopefully this should be the issue that was hitting fast/workers/worker-gc2.html on Qt. With a bit of luck there's now just the build dependency problem to resolve. 342299 13 benjamin 2011-01-30 08:30:14 -0800 Uh, shouldn't this be closed? 547967 14 ossy 2012-02-02 10:26:22 -0800 (In reply to comment #13) > Uh, shouldn't this be closed? Yes.