User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:55.0) Gecko/20100101 Firefox/55.0 Build ID: 20170313155736 Steps to reproduce: Run a build with cset Bug 1337043 cset 985d9b83325f with an about:page tab to be restored, or in session history. Mine was a win8/64 opt build on win10/64 system. Actual results: Firefox startup will not complete, on either first or subsequent attempts. Two tasks run...which have to be ended via task manager. Expected results: Firefox should start up all the way.
FYI: Just in case it's somehow relevant, the pages that bit me were about: and about:buildconfig
Tomcat, I'd suggest backing out bug 1337043 from inbound before it merges over to m-c nightly.
backed out in https://hg.mozilla.org/integration/mozilla-inbound/rev/62dd2dbd728b thanks aja for notifying us.