1659866 - Inspector doesn't show any rules

Status: RESOLVED FIXED

(DevTools :: about:debugging, defect, P2)

Description

[Karl Dubost💡 :karlcow]

Attachment: inspector in remote debugging

Setup:

• Desktop: Firefox Nightly 81.0a1 (2020-08-18) (64-bit) macOS 10.15.6 (19G2021)
• Mobile: Firefox Nightly 81.0a1-20200813092915 Android 10. Pixel 2

1. Mobile: Go to https://www.usedcarsni.com/cars (or any websites)
2. Desktop: Go to about:debugging
3. Open the remote debugger context
4. Click on inspector
5. select a node

Expected:
Have the CSS rules displayed in the center column

Actual:
All CSS rules are hidden.

Comment 1

[Dennis Schubert [:denschub]]

Note that I'm seeing a lot of

Error: Protocol error (NS_ERROR_UNEXPECTED): Component returned failure code: 0x8000ffff (NS_ERROR_UNEXPECTED) [nsIPrefBranch.getCharPref] from: server0.conn1.child40/pagestyle26 (resource://devtools/server/actors/compatibility.js:104:0)

in the browser console.

Comment 2

[Julian Descottes [:jdescottes]]

Attachment: Bug 1659866 - Add a setter for isTopLevelDocument on Node Front for backward compatibility

Comment 3

[Julian Descottes [:jdescottes]]

I spotted one backward compatibility issue, but that's probably not what you are experiencing here. Mine also makes the markup view go blank. I will look into the compatibility actor report from comment 1.

Comment 4

[Julian Descottes [:jdescottes]]

Ok pref("devtools.inspector.compatibility.target-browsers", ""); should be moved to https://searchfox.org/mozilla-central/source/modules/libpref/init/all.js otherwise it will be undefined on Fenix

Comment 5

[Julian Descottes [:jdescottes]]

Attachment: Bug 1659866 - Move server-side devtools pref for Compatibility panel to modules/libpref/init/all.js

Depends on D87603

Comment 6

[Julian Descottes [:jdescottes]]

Attachment: Bug 1659866 - Add try/catch around CompatibilityActor::getNodeCssIssues (fails due to missing preference)

Depends on D87611

Comment 7

[Julian Descottes [:jdescottes]]

Attachment: Bug 1659866 - Set a default value for target-browsers from the client

Depends on D87611

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/be6efbcfec5d
Add a setter for isTopLevelDocument on Node Front for backward compatibility r=daisuke
https://hg.mozilla.org/integration/autoland/rev/c9645c284601
Move server-side devtools pref for Compatibility panel to modules/libpref/init/all.js r=daisuke
https://hg.mozilla.org/integration/autoland/rev/103c9f61a101
Set a default value for target-browsers from the client r=daisuke

Comment 9

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/be6efbcfec5d
https://hg.mozilla.org/mozilla-central/rev/c9645c284601
https://hg.mozilla.org/mozilla-central/rev/103c9f61a101

Comment 10

[Karl Dubost💡 :karlcow]

Attachment: Capture d’écran 2020-08-26 à 08.29.58.png

Julian,

This is still busted for me as of today.
Is it the same for you?

macOS 10.15.6 (19G2021)
desktop Firefox Nightly 82.0a1 (2020-08-25) (64-bit)

Android 10
mobile Firefox Nightly 200825 06:07 (Build #2015759987)
81.0a1-20200820093209

just to stress that it is quite important for the daily debugging work on diagnosing issues for Firefox (for the webcompat team).

Thanks for any progress, and tell me how I can help you with better information.

Comment 11

[Mike Taylor [:miketaylr]]

Attachment: still broken

Comment 12

[Mike Taylor [:miketaylr]]

[Tracking Requested - why for this release]: Remote debugging inspector is broken. It would nice to not ship this to release?

Comment 13

[Julian Descottes [:jdescottes]]

While testing this morning I spotted another regression caused by Bug 1660266, which I am fixing via Bug 1662058 on the server (will file another Bug to add a workaround on the client).

To workaround this, you can set a default value for the missing pref.
Run Services.prefs.setBoolPref("devtools.overflow.debugging.enabled", false) in the console of the "Multiprocess toolbox" for Fenix.

After setting a default value, the inspector works for me.
Firefox desktop: latest central
Firefox mobile: Nightly 200829 06:05

Note that the Fenix build mentioned in the previous comments (81.0a1-20200820093209) does not include the fix that initially landed here, it is in the next one: https://ftp.mozilla.org/pub/firefox/nightly/2020/08/2020-08-20-21-21-07-mozilla-central/ . This means it didn't include the server side fix, which can explain why it didn't work for you? I am a bit surprised that the client side workaround in https://hg.mozilla.org/mozilla-central/rev/103c9f61a101 didn't properly create the preference.

Can you please test again?

Comment 14

[Mike Taylor [:miketaylr]]

OK, yeah. That did work for me:

1. in Firefox Nightly, open about:debugging and connect to the latest Fenix Nightly build.
2. Select the device on the left, then go to Processes at the bottom and click Inspect from the Multiprocess Toolbox
3. Run Services.prefs.setBoolPref("devtools.overflow.debugging.enabled", false) in the console of the Multiprocess Toolbox (chrome://geckoview/content/geckoview.xhtml should be the selected frame/context/whatever, if not select it from the icon next to the meatballs icon)
4. Disconnect device from top of about:debugging (Disconnect button)
5. Hit Connect again from about:debugging

At this point, the Inspector works as expected.

Comment 15

[Karl Dubost💡 :karlcow]

Mike Steps worked for me too with

Mobile Nightly 200831 06:01
and Desktop Nightly 82.0a1 (2020-08-30) (64-bit)

Comment 16

[Julian Descottes [:jdescottes]]

Thanks for testing!

The issue with devtools.overflow.debugging.enabled is tracked by Bug 1662058, so I think we can close this.
I am also working on a more generic client side workaround with Bug 1662067.

Comment 17

[Ryan VanderMeulen [:RyanVM]]

Bug 1662058 was a new regression in 82, but this bug also affects 81? Is there something we can do to fix this on Beta still? Or are we saying that this bug was tracking two different problems - one fixed by the original patches and one subsequent regression fixed by bug 1662058?

Comment 18

[Mike Taylor [:miketaylr]]

Thank you very much Julian for helping to get this working again. :)

Comment 19

[Julian Descottes [:jdescottes]]

(In reply to Ryan VanderMeulen [:RyanVM] from comment #17)

Bug 1662058 was a new regression in 82, but this bug also affects 81? Is there something we can do to fix this on Beta still? Or are we saying that this bug was tracking two different problems - one fixed by the original patches and one subsequent regression fixed by bug 1662058?

Normally the initial fix that landed here in 81 (https://hg.mozilla.org/mozilla-central/rev/c9645c284601) is sufficient to fix the issue.
There is some delay before Fenix incorporates changes so when Mike & Karl tested again, Fenix 81 didn't have the fix yet. But the "final" Fenix 81 contains the fix and doesn't require any new patch.

I am trying to update the flags in the bug accordingly.