[Tracking Requested - why for this release]: Mass devtools test bustage when Gecko 48 merges to Beta. https://treeherder.mozilla.org/logviewer.html#?job_id=18725820&repo=try

devtools/about-devtools-toolbox.js uses |Cm.isCIDRegistered| as a function, where |Cm| is defined as: const { Ci, Cu, Cm, components } = require("chrome"); I don't know much about this, but testing quickly locally in scratchpad, I always find isCIDRegistered to be undefined... However, this seems to work for me: let registrar = Cm.QueryInterface(Ci.nsIComponentRegistrar); registrar.isCIDRegistered I hope this helps.

I'm always surprised to see things being broken only after merges. Is it due to just preference differences or is there some code difference ?!? I imagine we can reproduce this issue with mozilla-central but with some tweaks in mozconfig to ask for a beta build? (In reply to Patrick Brosset [:pbro] from comment #1) > devtools/about-devtools-toolbox.js uses |Cm.isCIDRegistered| as a function, > where |Cm| is defined as: > const { Ci, Cu, Cm, components } = require("chrome"); > > I don't know much about this, but testing quickly locally in scratchpad, I > always find isCIDRegistered to be undefined... > > However, this seems to work for me: > > let registrar = Cm.QueryInterface(Ci.nsIComponentRegistrar); > registrar.isCIDRegistered > Yes, that makes sense, Cm isn't necessarely "interfaced" to nsIComponentRegistrar, I imagine with beta prefs we disable some code that does it before about-devtools-toolbox.js...

Comment on attachment 8737134 [details] [diff] [review] patch Review of attachment 8737134 [details] [diff] [review]: ----------------------------------------------------------------- I think the "usual" way is to use the return value of the QI call to call whatever method is needed, as in: https://dxr.mozilla.org/mozilla-central/source/js/xpconnect/tests/unit/test_xpcomutils.js#141 and many others. Can you do that for this case?

Per QueryInterface behavior, it shouldn't be necessary. But it is surprising to see so many usage where only the result of QI is used.

Ryan, just noticing that the target milestone is 48 but this landed in m-c (49) Does anything need uplift here? For your permafail bugs in general, I'll mark them as blockers.

^^

It landed on m-c prior to Gecko 48 merging to Aurora, so we're good.