Firefox have enabled optimization for their debug builds to make tests run faster and Thunderbird should consider doing the same. standard8 suggested we start with enabling optimizations on try server.
Moving to Thunderbird land as the configs are in-tree now.
Created attachment 622367 [details] [diff] [review] The fix So now we've got the new automation with xpcshell and mozmill tests, turning on optimize is a clear winner generally by at least 10 mins per run. Mac actually already has optimize turned on for debug (because of the way I copied the files), so no changes needed there.