User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0a2) Gecko/20110826 Firefox/8.0a2 Build ID: 20110826042012 Steps to reproduce: I opened the Help / Troubleshooting menu item in Thunderbird beta 7.0b1 and clicked the about:buildconfig link. Actual results: The about:buildconfig page opened, but the "Built from" link told me to Source info about the underlying Firefox repository, not about Thunderbird. In this case, the "Built from" link was http://hg.mozilla.org/releases/mozilla-beta/rev/00f56713eab6 , so it clearly goes to the mozilla-beta repository. Expected results: "Built from" link should have told me the relevant changeset from the Thunderbird comm-beta repository. There might possibly also be info about the underlying Firefox repository, but the main focus should be on Thunderbird information. Currently there seems to be no easy way to find out the Thunderbird source changeset in mercurial repository from the Thunderbird client.