[taskcluster 2026-01-05 16:55:30.075Z] Task ID: ZQB0qfd5RuSM1sUvOKLu7A
[taskcluster 2026-01-05 16:55:30.075Z] Worker ID: 6252617971038311135
[taskcluster 2026-01-05 16:55:30.075Z] Worker Group: us-central1-f
[taskcluster 2026-01-05 16:55:30.075Z] Worker Node Type: projects/757942385826/machineTypes/n2-standard-4
[taskcluster 2026-01-05 16:55:30.075Z] Worker Pool: proj-wpt/ci
[taskcluster 2026-01-05 16:55:30.075Z] Worker Version: 46.1.0
[taskcluster 2026-01-05 16:55:30.075Z] Public IP: 34.72.157.140
[taskcluster 2026-01-05 16:55:30.075Z] Hostname: proj-wpt-ci-hbwfdoqysraxyzaapzd00q

[taskcluster 2026-01-05 16:55:31.026Z] === Task Starting ===
+ '[' '' ']'
+ '[' -d /etc/profile.d ']'
+ for i in /etc/profile.d/*.sh
+ '[' -r /etc/profile.d/01-locale-fix.sh ']'
+ . /etc/profile.d/01-locale-fix.sh
+++ /usr/bin/locale-check C.UTF-8
++ eval
+ for i in /etc/profile.d/*.sh
+ '[' -r /etc/profile.d/apps-bin-path.sh ']'
+ . /etc/profile.d/apps-bin-path.sh

...(318 lines hidden)...

Failed to read: session.screen0.slit.autoHide
Setting default value
Failed to read: session.screen0.slit.maxOver
Setting default value
Failed to read: session.screen0.slit.placement
Setting default value
Failed to read: session.screen0.slit.alpha
Setting default value
Failed to read: session.screen0.slit.onhead
Setting default value
Failed to read: session.screen0.slit.layer
Setting default value
Failed to read: session.screen0.toolbar.autoHide
Setting default value
Failed to read: session.screen0.toolbar.maxOver
Setting default value
Failed to read: session.screen0.toolbar.visible
Setting default value
Failed to read: session.screen0.toolbar.alpha
Setting default value
Failed to read: session.screen0.toolbar.layer
Setting default value
Failed to read: session.screen0.toolbar.onhead
Setting default value
Failed to read: session.screen0.toolbar.placement
Setting default value
Failed to read: session.screen0.toolbar.height
Setting default value
Failed to read: session.screen0.iconbar.mode
Setting default value
Failed to read: session.screen0.iconbar.alignment
Setting default value
Failed to read: session.screen0.iconbar.iconWidth
Setting default value
Failed to read: session.screen0.iconbar.iconTextPadding
Setting default value
Failed to read: session.screen0.iconbar.usePixmap
Setting default value
 0:00.00 INFO Set tests_root to /home/test/web-platform-tests
 0:00.00 INFO Set metadata_root to /home/test/web-platform-tests
 0:00.00 INFO Set manifest_update to True
 0:00.00 INFO Set manifest_download to True
mem avail: 14785 of 15806 MiB (93.54%), swap free:    0 of    0 MiB ( 0.00%)
 0:14.31 INFO Identified 3 affected tests
 0:14.31 INFO Using certutil /usr/bin/certutil
 0:14.31 INFO Downloading geckodriver
 0:14.31 INFO Attempting to install webdriver from nightly
 0:14.89 INFO Extracted geckodriver to /home/test/web-platform-tests/_venv3/bin/geckodriver
 0:14.89 INFO Installed b'geckodriver 0.36.0 (d8f2204a567d 2025-12-25 08:29 +0000)'
 0:19.17 INFO Getting profile data from git ref 33bba5cfe4a89dda0ee07fa9fbac578353713fd3
 0:19.43 INFO Test prefs downloaded to /home/test/web-platform-tests/_venv3/profiles/33bba5cfe4a89dda0ee07fa9fbac578353713fd3/148.0a1
[1321] Sandbox: CanCreateUserNamespace() clone() failure: EPERM
 0:19.53 mozversion INFO application_buildid: 20260105095346
 0:19.54 mozversion INFO application_changeset: 906931f3ec40d7cf59752fdfb019736310aa2183
 0:19.54 mozversion INFO application_display_name: Firefox Nightly
 0:19.54 mozversion INFO application_id: {ec8030f7-c20a-464f-9b0e-13a3a9e97384}
 0:19.54 mozversion INFO application_name: Firefox
 0:19.54 mozversion INFO application_remotingname: firefox-nightly
 0:19.54 mozversion INFO application_repository: https://hg.mozilla.org/mozilla-central
 0:19.54 mozversion INFO application_vendor: Mozilla
 0:19.54 mozversion INFO application_version: 148.0a1
 0:19.54 mozversion INFO platform_buildid: 20260105095346
 0:19.54 mozversion INFO platform_changeset: 906931f3ec40d7cf59752fdfb019736310aa2183
 0:19.54 mozversion INFO platform_repository: https://hg.mozilla.org/mozilla-central
 0:19.54 mozversion INFO platform_version: 148.0a1
 0:24.83 INFO Installed font: Ahem.ttf
 0:25.71 wptserve INFO Starting http server on http://127.0.0.1:8000
 0:25.75 wptserve INFO Starting http server on http://127.0.0.1:8001
 0:25.76 wptserve INFO Starting https server on https://127.0.0.1:8443
 0:25.76 wptserve INFO Starting http server on http://127.0.0.1:8003
 0:25.77 wptserve INFO Starting https server on https://127.0.0.1:8444
 0:25.79 wptserve INFO Starting http server on http://127.0.0.1:8002
 0:25.80 wptserve INFO Starting https server on https://127.0.0.1:8446
 0:25.80 wptserve INFO Starting https server on https://127.0.0.1:8445
 0:25.82 wptserve INFO Create socket on: (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 8889))
 0:25.82 wptserve INFO Bind on: (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 8889))
 0:25.82 wptserve INFO Listen on: (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 8889))
 0:25.82 wptserve INFO Create socket on: (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 8888))
 0:25.82 wptserve INFO Bind on: (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 8888))
 0:25.82 wptserve INFO Listen on: (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 8888))
 0:25.84 wptserve INFO Starting http2 server on https://127.0.0.1:9000
 0:25.89 wptserve INFO Starting WebTransport over HTTP/3 server on 127.0.0.1:11000
 0:26.25 SUITE_START: web-platform-test - running 3 tests
 0:44.13 INFO Using 1 child processes
 0:44.16 INFO Setting up ssl
 0:44.18 certutil Full command: /usr/bin/certutil -N -d /tmp/tmpum7x2a1w.mozrunner -f /tmp/tmpum7x2a1w.mozrunner/.crtdbpw
certutil b''
 0:44.20 certutil b''
 0:44.21 certutil b'\nCertificate Nickname                                         Trust Attributes\n                                                             SSL,S/MIME,JAR/XPI\n\nweb-platform-tests                                           CT,, \n'
 0:44.21 INFO Application command: /home/test/build/firefox/firefox --marionette --remote-allow-system-access about:blank -profile /tmp/tmplr7addi2
 0:44.23 INFO Starting runner
 0:44.25 pid:1429 Full command: /home/test/build/firefox/firefox --marionette --remote-allow-system-access about:blank
pid:1429 [1429] Sandbox: CanCreateUserNamespace() clone() failure: EPERM
 0:45.01 pid:1429 1767632271478	Marionette	INFO	Marionette enabled
 0:45.11 pid:1429 1767632271583	Marionette	INFO	Listening on port 37793
Failed to read: session.screen0.titlebar.left
Setting default value
Failed to read: session.screen0.titlebar.right
Setting default value
 0:47.91 pid:1429 console.error: services.settings:
 0:47.91 pid:1429   Message: EmptyDatabaseError: "main/nimbus-desktop-experiments" has not been synced yet
 0:47.91 pid:1429   Stack:
 0:47.91 pid:1429     EmptyDatabaseError@resource://services-settings/Database.sys.mjs:19:5
 0:47.92 pid:1429 list@resource://services-settings/Database.sys.mjs:96:13
 0:48.07 pid:1429 console.warn: BackupService: "There was an error while trying to get the Document's directory" [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIProperties.get]"  nsresult: "0x80004005 (NS_ERROR_FAILURE)"  location: "JS frame :: resource:///modules/backup/BackupService.sys.mjs :: get docsDirFolderPath :: line 1245"  data: no]
 0:48.19 TEST_START: /html/semantics/forms/the-select-element/customizable-select/select-appearance-sizing-in-flex.html
 0:48.42 pid:1429 1767632274893	Marionette	INFO	Testing http://web-platform.test:8000/html/semantics/forms/the-select-element/customizable-select/select-appearance-sizing-in-flex.html == http://web-platform.test:8000/html/semantics/forms/the-select-element/customizable-select/select-appearance-sizing-in-flex-ref.html
 0:48.67 pid:1429 1767632275142	Marionette	INFO	No differences allowed
 0:48.68 TEST_END: PASS
 0:48.68 INFO Restarting browser for new test environment
 0:48.70 pid:1429 1767632275169	Marionette	INFO	Stopped listening on port 37793
 0:49.32 INFO Browser exited with return code -15
 0:49.20 INFO Closing logging queue
 0:49.21 INFO queue closed
 0:49.33 INFO Application command: /home/test/build/firefox/firefox --marionette --remote-allow-system-access about:blank -profile /tmp/tmphlyyxz95
 0:49.34 INFO Starting runner
 0:49.34 pid:1751 Full command: /home/test/build/firefox/firefox --marionette --remote-allow-system-access about:blank
pid:1751 [1751] Sandbox: CanCreateUserNamespace() clone() failure: EPERM
 0:49.83 pid:1751 1767632276294	Marionette	INFO	Marionette enabled
 0:49.98 pid:1751 1767632276451	Marionette	INFO	Listening on port 34597
 0:49.99 pid:1751 [Parent 1751, Main Thread] WARNING: Failed to create DBus proxy for org.a11y.Bus: Could not connect: Connection refused
 0:49.99 pid:1751 : 'glib warning', file /builds/worker/checkouts/gecko/toolkit/xre/nsSigHandlers.cpp:201
 0:49.99 pid:1751 ** (firefox-nightly:1751): WARNING **: 16:57:56.459: Failed to create DBus proxy for org.a11y.Bus: Could not connect: Connection refused
 0:52.24 pid:1751 console.warn: BackupService: "There was an error while trying to get the Document's directory" [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIProperties.get]"  nsresult: "0x80004005 (NS_ERROR_FAILURE)"  location: "JS frame :: resource:///modules/backup/BackupService.sys.mjs :: get docsDirFolderPath :: line 1245"  data: no]
 0:52.49 pid:1751 console.error: services.settings:
 0:52.49 pid:1751   Message: EmptyDatabaseError: "main/nimbus-desktop-experiments" has not been synced yet
 0:52.49 pid:1751   Stack:
 0:52.49 pid:1751     EmptyDatabaseError@resource://services-settings/Database.sys.mjs:19:5
 0:52.49 pid:1751 list@resource://services-settings/Database.sys.mjs:96:13
 0:52.58 TEST_START: /html/semantics/forms/the-select-element/customizable-select/select-display-block.tentative.html
 0:53.49 WARNING Unexpected viewport size for /html/semantics/forms/the-select-element/customizable-select/select-display-block.tentative.html, (798, 598), expected (800, 600)
 0:53.59 WARNING Unexpected viewport size for /html/semantics/forms/the-select-element/customizable-select/select-display-block-ref.html, (798, 598), expected (800, 600)
 0:53.60 INFO Image hashes didn't match on page 1, checking pixel differences
 0:53.67 INFO Found 2507 pixels different, maximum difference per channel 255 on page 1
 0:53.67 INFO Allowed 0-1 pixels different, maximum difference per channel 0-3
 0:53.67 TEST_END: FAIL, expected PASS - /html/semantics/forms/the-select-element/customizable-select/select-display-block.tentative.html ['99f3019528712539e5d6d482a77942b61d9bd4c4']
/html/semantics/forms/the-select-element/customizable-select/select-display-block-ref.html ['3375452bd45f5721849a886a2371dc0a15a817cd']
 0:53.67 INFO Restarting browser for new test environment
 0:53.68 pid:1751 1767632280153	Marionette	INFO	Stopped listening on port 34597
 0:54.47 INFO Browser exited with return code -15
 0:54.35 INFO Closing logging queue
 0:54.35 INFO queue closed
 0:54.48 INFO Application command: /home/test/build/firefox/firefox --marionette --remote-allow-system-access about:blank -profile /tmp/tmpyej60owy
 0:54.50 INFO Starting runner
 0:54.50 pid:2112 Full command: /home/test/build/firefox/firefox --marionette --remote-allow-system-access about:blank
pid:2112 [2112] Sandbox: CanCreateUserNamespace() clone() failure: EPERM
 0:55.06 pid:2112 1767632281531	Marionette	INFO	Marionette enabled
 0:55.18 pid:2112 1767632281649	Marionette	INFO	Listening on port 48155
 0:56.26 pid:2112 console.error: services.settings:
 0:56.26 pid:2112   Message: EmptyDatabaseError: "main/nimbus-desktop-experiments" has not been synced yet
 0:56.26 pid:2112   Stack:
 0:56.26 pid:2112     EmptyDatabaseError@resource://services-settings/Database.sys.mjs:19:5
 0:56.26 pid:2112 list@resource://services-settings/Database.sys.mjs:96:13
 0:56.39 pid:2112 console.warn: BackupService: "There was an error while trying to get the Document's directory" [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIProperties.get]"  nsresult: "0x80004005 (NS_ERROR_FAILURE)"  location: "JS frame :: resource:///modules/backup/BackupService.sys.mjs :: get docsDirFolderPath :: line 1245"  data: no]
 0:56.57 TEST_START: /html/semantics/forms/the-select-element/customizable-select/select-grid-before-after.html
 0:56.63 pid:2112 1767632283099	Marionette	INFO	Testing http://web-platform.test:8000/html/semantics/forms/the-select-element/customizable-select/select-grid-before-after.html == http://web-platform.test:8000/html/semantics/forms/the-select-element/customizable-select/select-grid-before-after-ref.html
 0:56.87 pid:2112 1767632283342	Marionette	INFO	No differences allowed
 0:56.89 TEST_END: FAIL, expected PASS - Testing http://web-platform.test:8000/html/semantics/forms/the-select-element/customizable-select/select-grid-before-after.html == http://web-platform.test:8000/html/semantics/forms/the-select-element/customizable-select/select-grid-before-after-ref.html
Found 4335 pixels different, maximum difference per channel 255

 0:56.89 INFO No more tests
 0:56.92 pid:2112 1767632283389	Marionette	INFO	Stopped listening on port 48155
 0:57.52 INFO Browser exited with return code -15
 0:57.43 INFO Closing logging queue
 0:57.43 INFO queue closed
 0:57.53 SUITE_END

web-platform-test
~~~~~~~~~~~~~~~~~
Ran 3 checks (3 tests)
Expected results: 1
Unexpected results: 2
  test: 2 (2 fail)

Unexpected Results
------------------
FAIL /html/semantics/forms/the-select-element/customizable-select/select-display-block.tentative.html - /html/semantics/forms/the-select-element/customizable-select/select-display-block.tentative.html ['99f3019528712539e5d6d482a77942b61d9bd4c4']
/html/semantics/forms/the-select-element/customizable-select/select-display-block-ref.html ['3375452bd45f5721849a886a2371dc0a15a817cd']
FAIL /html/semantics/forms/the-select-element/customizable-select/select-grid-before-after.html - Testing http://web-platform.test:8000/html/semantics/forms/the-select-element/customizable-select/select-grid-before-after.html == http://web-platform.test:8000/html/semantics/forms/the-select-element/customizable-select/select-grid-before-after-ref.html
Found 4335 pixels different, maximum difference per channel 255
 0:57.53 INFO Got 2 unexpected results, with 0 unexpected passes
 0:57.53 wptserve INFO Stopped http server on 127.0.0.1:8001
 0:57.53 wptserve INFO Stopped http server on 127.0.0.1:8000
 0:57.53 wptserve INFO Stopped http server on 127.0.0.1:8002
 0:57.53 wptserve INFO Stopped http server on 127.0.0.1:8443
 0:57.54 wptserve INFO Stopped http server on 127.0.0.1:8003
 0:57.56 wptserve INFO Stopped http server on 127.0.0.1:8446
 0:57.56 wptserve INFO Stopped http server on 127.0.0.1:9000
 0:57.56 wptserve INFO Stopped WebTransport over HTTP/3 server on 127.0.0.1:11000
 0:57.56 wptserve INFO Stopped http server on 127.0.0.1:8444
 0:57.56 wptserve INFO Stopped http server on 127.0.0.1:8445
 0:57.78 wptserve INFO Close on: (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 8888))
 0:57.80 wptserve INFO Close on: (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 8889))
 0:57.83 INFO Removed font: Ahem.ttf
 0:57.85 INFO Closing logging queue
 0:57.86 INFO queue closed
 0:57.86 INFO Tolerating 2 unexpected results
[taskcluster 2026-01-05 16:58:06.010Z] === Task Finished ===
[taskcluster 2026-01-05 16:58:06.976Z] Successful task run with exit code: 0 completed in 156.902 seconds