178820 2017-10-25 11:57:05 -0700 REGRESSION(r223729): Speedometer 2.0 React-Redux-TodoMVC throws TypeError: undefined is not an object (evaluating 'this.moveChild') 2017-10-25 15:19:13 -0700 1 1 1 Unclassified WebKit New Bugs WebKit Nightly Build Unspecified Unspecified RESOLVED DUPLICATE 178834 https://bugs.webkit.org/show_bug.cgi?id=178834 P2 Normal --- 1 ryanhaddad webkit-unassigned cdumez dbates rniwa saam oldest_to_newest 1364362 0 ryanhaddad 2017-10-25 11:57:05 -0700 Running Speedometer (181 of 181) ERROR: CONSOLE MESSAGE: line 1: TypeError: undefined is not an object (evaluating 'this.moveChild') FAILED Finished: 42.359004 s https://build.webkit.org/builders/Apple%20El%20Capitan%20Release%20WK2%20%28Perf%29/builds/1473 1364364 1 ryanhaddad 2017-10-25 12:00:31 -0700 The last successful run was r223712: https://build.webkit.org/builders/Apple%20El%20Capitan%20Release%20WK2%20%28Perf%29/builds/1472 1364376 2 ryanhaddad 2017-10-25 12:10:43 -0700 It isn't clear to me from the error message what change caused this. 1364377 3 ryanhaddad 2017-10-25 12:11:37 -0700 https://trac.webkit.org/log/webkit/?action=stop_on_copy&mode=stop_on_copy&rev=223930&stop_rev=223913&limit=100&verbose=on 1364383 4 rniwa 2017-10-25 12:29:55 -0700 Likely culprits: https://trac.webkit.org/changeset/223715 https://trac.webkit.org/changeset/223720 1364396 5 rniwa 2017-10-25 12:41:05 -0700 223727: ok 1364409 6 ryanhaddad 2017-10-25 12:59:08 -0700 (In reply to Ryan Haddad from comment #3) > https://trac.webkit.org/log/webkit/ > ?action=stop_on_copy&mode=stop_on_copy&rev=223930&stop_rev=223913&limit=100&v > erbose=on Sorry for the confusion, this should have been: https://trac.webkit.org/log/webkit/?action=stop_on_copy&mode=stop_on_copy&rev=223730&stop_rev=223713&limit=100&verbose=on 1364474 7 rniwa 2017-10-25 14:24:30 -0700 Confirmed the regression doesn't exist at r223727. "React-Redux-TodoMVC" is the one hitting this regression. 1364514 8 rniwa 2017-10-25 15:05:42 -0700 Hm.... in my local testing, I can't reproduce this at r223728. Re-bisecting. 1364521 9 rniwa 2017-10-25 15:12:47 -0700 Apparently, this is caused by https://trac.webkit.org/changeset/223729, which happens to enable the feature which was meant to be implemented by https://trac.webkit.org/changeset/223691 1364530 10 rniwa 2017-10-25 15:19:13 -0700 The culprit was rolled out in https://trac.webkit.org/changeset/223989. *** This bug has been marked as a duplicate of bug 178834 ***