1403938 - Investigate removing built-in Canvas Debugger in favour of WebExtension

Status: RESOLVED FIXED

(DevTools Graveyard :: Canvas Debugger, enhancement, P3)

Description

[Soledad Penades [:sole] [:spenades]]

The Canvas Debugger is one of our less popular features. But it is also not maintained, and not new features have been added in a while, while bugs and intermittents _do_ happen from time to time.

Additionally, it is built with XUL and it's hard to find people who are proficient on it in order to keep working on it.

This bug is to track:

- potential alternatives in the form of a WebExtension
- migration paths for panel users

Comment 1

[Yulia Startsev [:yulia] OOO until July 2026]

Attachment: Bug 1403938 - remove Canvas Debugger client; r=vporof

Assigning sole for now

Comment 2

[Yulia Startsev [:yulia] OOO until July 2026]

Attachment: Bug 1403938 - remove Canvas Debugger actor from the server; r=vporof

Depends on D14730

Comment 3

[Tim Nguyen :ntim]

This one is a bit hard to find, but this needs to be removed too: https://searchfox.org/mozilla-central/rev/5053031ba7621fa8f63f42de4c204ab3561e4e59/devtools/client/themes/toolbars.css#189 :)

Comment 4

[Andrei Ciure[:aciure]]

Backed out 13 changesets (bug 1342237, bug 1403944, bug 1403938, bug 1528296) for subsuite gpu failures

push that caused the failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception&classifiedState=unclassified&selectedJob=233374281&revision=285c56c2914625c8418613cdbe35436c355ea4dc

failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception&classifiedState=unclassified&selectedJob=233408962&searchStr=linux%2Cdebug%2Cmochitests%2Cwith%2Ce10s%2Ctest-linux32%2Fdebug-mochitest-gpu-e10s%2Cm-e10s%28gpu%29

backout: https://hg.mozilla.org/integration/autoland/rev/75b49fcc27432b8fbc25ea3c5226445fd25190df

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/488d49d434f8
remove Canvas Debugger client; r=vporof
https://hg.mozilla.org/integration/mozilla-inbound/rev/90579bc6554c
remove Canvas Debugger actor from the server; r=vporof

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9867bfb9fb4d
remove Canvas Debugger client; r=vporof
https://hg.mozilla.org/integration/autoland/rev/8d2a9c87c452
remove Canvas Debugger actor from the server; r=vporof

Comment 7

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/9867bfb9fb4d
https://hg.mozilla.org/mozilla-central/rev/8d2a9c87c452

Comment 8

[Starbeamrainbowlabs]

Why was the Canvas debugger silently removed without any warning????

I've just run into an issue with my 2D canvas drawing context code that I needed the canvas inspector for, and I'm just spent 1/2 hour trying to find it - only to run into this bug.

Spector.js is suggested as an alternative (link: https://addons.mozilla.org/en-US/firefox/addon/spector-js/#&gid=1&pid=2), but as far as I can tell it's only for WebGL contexts, which I'm not using (I'm using a 2D drawing context instead).

Does anyone know at least of an alternative to this? It was an essential feature that I used regularly when developing canvas-based applications.

I haven't done any canvas-based development for a while because of other University work pressures, but now that I'm back to it I'm shocked and rather disappointed.

Comment 9

[badunius]

Okay, and now there's no Spector.js (which is also useless to me for debugging 2d canvas context) nor Canvas Debugger. Nice.