Windows: TEST-UNEXPECTED-FAIL | C:\slave\test\build\tests\mozmill\startup-firstrun\test-menubar-collapsed.js | test-menubar-collapsed.js::test_main_menu_collapsed Linux: TEST-UNEXPECTED-FAIL | /builds/slave/test/build/tests/mozmill/startup-firstrun/test-menubar-collapsed.js | test-menubar-collapsed.js::test_main_menu_collapsed First seen: Sun Nov 12, 2017, 1:05:05 https://treeherder.mozilla.org/#/jobs?repo=comm-central&revision=c2bfe9667d82e4bf2ea04e07762140dac8a4ed4c M-C first bad: aabfc14671b55983e1c3053989a4c3b7c5 M-C last good: 57eb0baf17ce8678767abfbf17bdb0acfd C-C first bad: c2bfe9667d82 C-C last good: 5b6e551a23fb

Thanks, this is caused by bug 1371898, where the setting of autohide=true was removed from mailMigrator.js . It is also seen in my try run. If we are expecting to have autohide=true in new profiles, I am wondering why the setting is was in mailMigrator.js and not directly in the XUL file. I'll see in bug 791311 why this was implemented this way.

Branch day is tomorrow, so unless a fix here lands today (or bug 1371898 is backed out), this failure will go to beta. I don't know who would handle beta approval and uplifts these days in absence of a Thunderbird release manager.

Thanks for the reminder. Bug 1371898 isn't as critical so I better back it out to better analyze what is going on.

Fixed by backout of bug 1371898