2024934 - Perma devtools/client/shared/test/browser_outputparser.js | CSS property correctly parsed for color: color-mix(in srgb, red, blue, green) - Got "color-mix(in srgb, red, blue, green)" - when Gecko 150 merges to beta on 2026-03-23

Status: VERIFIED FIXED

(DevTools :: Inspector: Rules, defect)

Description

[rperta]

• Central-as-beta-simulation
• How to run these simulations
• Failure log
• Failure snippet:

[task 2026-03-20T10:56:02.925+00:00] 10:56:02     INFO - TEST-PASS | devtools/client/shared/test/browser_outputparser.js | CSS property correctly parsed for color: color-mix(in srgb, red, contrast-color(hsl(0 100 200)))
[task 2026-03-20T10:56:02.925+00:00] 10:56:02     INFO - Testing color: color-mix(in srgb, red, blue, green)
[task 2026-03-20T10:56:02.926+00:00] 10:56:02     INFO - Buffered messages finished
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - TEST-UNEXPECTED-FAIL | devtools/client/shared/test/browser_outputparser.js | CSS property correctly parsed for color: color-mix(in srgb, red, blue, green) - Got "color-mix(in srgb, red, blue, green)", expected "color-mix(in srgb, <span data-color=\"red\" class=\"color-swatch-container\"><span class=\"test-class\" style=\"background-color:red\" tabindex=\"0\" role=\"button\" data-color-function=\"color-mix\"></span><span>red</span></span>, <span data-color=\"blue\" class=\"color-swatch-container\"><span class=\"test-class\" style=\"background-color:blue\" tabindex=\"0\" role=\"button\" data-color-function=\"color-mix\"></span><span>blue</span></span>, <span data-color=\"green\" class=\"color-swatch-container\"><span class=\"test-class\" style=\"background-color:green\" tabindex=\"0\" role=\"button\" data-color-function=\"color-mix\"></span><span>green</span></span>)"
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - chrome://mochikit/content/browser-test.js:test_is:1913
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - chrome://mochitests/content/browser/devtools/client/shared/test/browser_outputparser.js:testParseCssProperty:414
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - chrome://mochitests/content/browser/devtools/client/shared/test/browser_outputparser.js:performTest:31
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - chrome://mochitests/content/browser/devtools/client/shared/test/browser_outputparser.js:null:16
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - chrome://mochikit/content/browser-test.js:handleTask:1376
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - chrome://mochikit/content/browser-test.js:_runTaskBasedTest:1466
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - chrome://mochikit/content/browser-test.js:Tester_execTest:1617
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - chrome://mochikit/content/browser-test.js:nextTest/<:1356
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:SimpleTest.waitForFocus/<:1060
[task 2026-03-20T10:56:02.929+00:00] 10:56:02     INFO - Testing color: color-mix(in srgb, red)
[task 2026-03-20T10:56:02.930+00:00] 10:56:02     INFO - GECKO(6253) | [dump-scope] Serializing variables for frame: chrome://mochikit/content/browser-test.js @ 36:9
[task 2026-03-20T10:56:02.930+00:00] 10:56:02     INFO - GECKO(6253) | [dump-scope] Serializing variables for frame: chrome://mochikit/content/browser-test.js @ 1864:3
[task 2026-03-20T10:56:02.931+00:00] 10:56:02     INFO - GECKO(6253) | [dump-scope] Serializing variables for frame: chrome://mochikit/content/browser-test.js @ 1902:9
[task 2026-03-20T10:56:02.931+00:00] 10:56:02     INFO - GECKO(6253) | [dump-scope] Serializing variables for frame: chrome://mochikit/content/browser-test.js @ 1913:10
[task 2026-03-20T10:56:02.932+00:00] 10:56:02     INFO - GECKO(6253) | [dump-scope] Serializing variables for frame: chrome://mochitests/content/browser/devtools/client/shared/test/browser_outputparser.js @ 414:7
[task 2026-03-20T10:56:02.932+00:00] 10:56:02     INFO - GECKO(6253) | [dump-scope] Serializing variables for frame: chrome://mochitests/content/browser/devtools/client/shared/test/browser_outputparser.js @ 31:23
[task 2026-03-20T10:56:02.933+00:00] 10:56:02     INFO - GECKO(6253) | [dump-scope] Serializing variables for frame: chrome://mochitests/content/browser/devtools/client/shared/test/browser_outputparser.js @ 16:9
[task 2026-03-20T10:56:02.933+00:00] 10:56:02     INFO - GECKO(6253) | [dump-scope] Serializing variables for frame: chrome://mochikit/content/browser-test.js @ 1376:26
[task 2026-03-20T10:56:02.934+00:00] 10:56:02     INFO - GECKO(6253) | [dump-scope] Serializing variables for frame: chrome://mochikit/content/browser-test.js @ 1466:18
[task 2026-03-20T10:56:02.934+00:00] 10:56:02     INFO - GECKO(6253) | [dump-scope] Saving scope variables as a JSON file: /builds/worker/workspace/build/blobber_upload_dir/scope-variables-1774004162699-browser_outputparser.js_16_9.json
[task 2026-03-20T10:56:02.935+00:00] 10:56:02     INFO - Not taking screenshot here: see the one that was previously logged
[task 2026-03-20T10:56:02.936+00:00] 10:56:02     INFO - TEST-UNEXPECTED-FAIL | devtools/client/shared/test/browser_outputparser.js | CSS property correctly parsed for color: color-mix(in srgb, red) - Got "color-mix(in srgb, red)", expected "color-mix(in srgb, <span data-color=\"red\" class=\"color-swatch-container\"><span class=\"test-class\" style=\"background-color:red\" tabindex=\"0\" role=\"button\" data-color-function=\"color-mix\"></span><span>red</span></span>)"
[task 2026-03-20T10:56:02.936+00:00] 10:56:02     INFO - chrome://mochikit/content/browser-test.js:test_is:1913
[task 2026-03-20T10:56:02.936+00:00] 10:56:02     INFO - chrome://mochitests/content/browser/devtools/client/shared/test/browser_outputparser.js:testParseCssProperty:414
[task 2026-03-20T10:56:02.936+00:00] 10:56:02     INFO - chrome://mochitests/content/browser/devtools/client/shared/test/browser_outputparser.js:performTest:31
[task 2026-03-20T10:56:02.936+00:00] 10:56:02     INFO - chrome://mochitests/content/browser/devtools/client/shared/test/browser_outputparser.js:null:16
[task 2026-03-20T10:56:02.936+00:00] 10:56:02     INFO - chrome://mochikit/content/browser-test.js:handleTask:1376
[task 2026-03-20T10:56:02.936+00:00] 10:56:02     INFO - chrome://mochikit/content/browser-test.js:_runTaskBasedTest:1466
[task 2026-03-20T10:56:02.936+00:00] 10:56:02     INFO - chrome://mochikit/content/browser-test.js:Tester_execTest:1617
[task 2026-03-20T10:56:02.936+00:00] 10:56:02     INFO - chrome://mochikit/content/browser-test.js:nextTest/<:1356
[task 2026-03-20T10:56:02.936+00:00] 10:56:02     INFO - chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:SimpleTest.waitForFocus/<:1060
[task 2026-03-20T10:56:02.937+00:00] 10:56:02     INFO - TEST-PASS | devtools/client/shared/test/browser_outputparser.js | captain, we have the div
[task 2026-03-20T10:56:02.937+00:00] 10:56:02     INFO - TEST-PASS | devtools/client/shared/test/browser_outputparser.js | CSS property correctly parsed

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

:nchevobbe, since you are the author of the regressor, bug 2024544, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 2

[Donal Meehan [:dmeehan]]

Fx150 merges to beta on Monday so there's little time to fix this

Comment 3

[Nicolas Chevobbe [:nchevobbe]]

we probably need to set the pref that is nightly only for now: https://searchfox.org/firefox-main/rev/8a756a3ed58c5fb8aed589d5e89a43f55b8bdc32/modules/libpref/init/StaticPrefList.yaml#10315-10319

- name: layout.css.color-mix-multi-color.enabled
  type: RelaxedAtomicBool
  value: @IS_NIGHTLY_BUILD@
  mirror: always
  rust: true

I'll have a patch ready soon

Comment 4

[Nicolas Chevobbe [:nchevobbe]]

Attachment: Bug 2024934 - [devtools] Fix browser_outputparser.js beta perma-fail. r=#devtools.

Set layout.css.color-mix-multi-color.enabled to true (it's only enabled on Nightly
at the moment), so the new assertions added for multicolor color-mix still work.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/3767910e4f3c
https://hg.mozilla.org/integration/autoland/rev/a9e9220505ff
[devtools] Fix browser_outputparser.js beta perma-fail. r=devtools-reviewers,jdescottes.

Comment 6

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/a9e9220505ff

Comment 7

[Cristian Tuns]

The patch is working in today's beta-simulation: https://treeherder.mozilla.org/jobs?repo=try&group_state=expanded&revision=a0aba26fcb85dce43811253c9abae6ad428fd7db&searchStr=linux%2C24.04%2Cdebug%2Cmochitests%2Ctest-linux2404-64%2Fdebug-mochitest-devtools-chrome%2Cdt

Comment 8

[Intermittent Failures Robot]

13 failures were associated with this bug in the last 7 days.

Repository breakdown:

• try: 13

Table

	http3	no_variant
linux2404-x86_64/asan		1
linux2404-x86_64/debug	1	6
linux2404-x86_64/opt		1
linux2404-x86_64/tsan		1
windows11-x86_64/asan		1
windows11-x86_64/debug		1
windows11-x86_64/opt		1

For more details, see:

https://treeherder.mozilla.org/intermittent-failures/bugdetails?bug=2024934&startday=2026-03-16&endday=2026-03-22&tree=all