It seems like the blocklist service isn't disabled in mochitest-a11y as I just hit this failure: 19:34:39 INFO - System JS : ERROR jar:file:///C:/slave/test/build/application/firefox/omni.ja!/components/nsBlocklistService.js:70 19:34:39 INFO - NS_ERROR_XPC_GS_RETURNED_FAILURE: Component returned failure code: 0x80570016 (NS_ERROR_XPC_GS_RETURNED_FAILURE) [nsIJSCID.getService] 19:34:39 INFO - System JS : ERROR jar:file:///C:/slave/test/build/application/firefox/omni.ja!/components/nsBlocklistService.js:768 19:34:39 INFO - ReferenceError: gApp is not defined We can possibly just disable blocklist checking with extensions.blocklist.enabled in these mochitests like we do for reftests.
this seems to become more a perma-orange on the trees.
This is just log spam (now that the TBPL parser is picking this up too), it's not causing the runs to fail (but yeah it's still annoying me too!) :-)
(Note this occurs on green runs too, see bug 897031 comment 0 :-))