Closed Bug 1369399 Opened 6 years ago Closed 6 years ago

[Project Dawn] Firefox Developer Edition 54b12 disables e10s


(Firefox :: General, defect)

54 Branch
Windows 10
Not set



Firefox 55
Tracking Status
firefox-esr52 --- unaffected
firefox53 --- unaffected
firefox54 --- wontfix
firefox55 --- fixed


(Reporter: mrdokenny, Assigned: mrbkap)



(Keywords: regression)


(2 files)

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:54.0) Gecko/20100101 Firefox/54.0
Build ID: 20170529025115

Steps to reproduce:

1. Download or upgrade to Firefox Developer Edition 54b12

Actual results:

E10s is disabled without any message in about:troubleshooting saying 0/1 (Disabled)

Expected results:

E10s should not be disabled even with no addons or compatible addons.

Also another side effect is that force-enabling e10s causes any installed/updated addon (even WebExtensions) to ask for a Firefox restart. See screenshot.
Has STR: --- → yes
Keywords: regression
OS: Unspecified → Windows 10
This sounds troublesome. I could see there being differences in e10s status now that RELEASE_OR_BETA is set for DevEdition when it wasn't previously.
Component: Untriaged → General
Ever confirmed: true
Thanks for noticing this, Kenny!
Assignee: nobody → mrbkap
Comment on attachment 8875043 [details]
Bug 1369399 - Re-enable e10s for DevEdition.
Attachment #8875043 - Flags: review?(felipc) → review+
Pushed by
Re-enable e10s for DevEdition. r=Felipe
Closed: 6 years ago
Resolution: --- → FIXED
Target Milestone: --- → Firefox 55
DevEdition is moving to Gecko 55 next week and we're already in the release candidate phase of 54, so we won't be fixing DevEdition 54 at this point.
Does this patch also fix the WebExtension restarting issue or is it something else?
Flags: needinfo?(mrbkap)
Yes, this also fixes the WebExtension restarting issue (as far as I can tell).
Flags: needinfo?(mrbkap)
I tested these builds here on a new profile and there's still some problems.

The good news is e10s is still enabled on a new profile but WebExtensions are still asking for a restart (WebExtensions don't ask for a restart in non-e10s mode).

Also e10s can be disabled by a WebExtension using these STR on a new profile:

1. Install 55b1 candidate builds
2. Open up 55b1 Developer Edition and install a WebExtension
3. The WebExtension will ask for a restart. Click Restart.
4. Firefox restarts (e10s is still enabled)
5. Exit and Open up Firefox again (2nd restart)

After step 5, e10s is disabled saying this time in about:troubleshooting (0/1) Disabled by addons, despite only having a WebExtension.
Flags: needinfo?(mrbkap)
I can reproduce that. I don't know how I didn't reproduce it before. I'll file a new bug for it.
Flags: needinfo?(mrbkap)
Blocks: 1374492
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