Oh. It's arguable whether mach try should specifically support this. --upload-xdbs is not processed by any try syntax parser. It relies on everything but mach try allowing arbitrary strings in the commit messages, even ones that being with "try:". If this is not desireable for mach try, and I would certainly be sympathetic to that point of view, I am fine with changing my syntax to something less troublesome. --job-options=upload-xdbs perhaps? Details: The script that runs these builds in taskcluster grabs out the commit message and "parses" it on its own. Where parsing means grepping for the substring --upload-xdbs. Note that because this is not done via the try syntax parser, if I happen to fix this with the commit message "Replace --upload-xdbs with XXX", it will upload the xdbs for the mozilla-inbound hazard jobs spawned by that push. :-)

This is the patch I've been using to hack around this. It just always adds the message.

Pushed by sfink@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/296f060687f7 Add --upload-xdbs option to mach try, r=chmanchester

Thanks.