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Current Desktop beta cycle:
138
Uplifts by Product
114 uplifts
Firefox
49
Core
35
N/A
7
WebExtensions
4
Toolkit
4
DevTools
3
Firefox for Android
3
Firefox Build System
3
Remote Protocol
2
External Software Affecting Firefox
1
Focus
1
Testing
1
Thunderbird
1
138.0b1
No uplifts
(contains all the patches landed during the nightly cycle)
Show crashes
Hide crashes
OOM | small
(12.43%)
Known top crash
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::AutoEnterOOMUnsafeRegion::crash | js::gc::AllocateTenuredCellInGC
(8.28%)
1472062
mozilla::GetBootstrap::<T>::operator()
(4.73%)
1816848
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | mozilla::BitSet<T>::FindNext
(3.55%)
1949316
nsFind::FindFromRangeBoundaries
(3.55%)
1949877
AsyncShutdownTimeout | AddonManager: Waiting to start provider shutdown. | AddonRepository Background Updater
(2.96%)
1841444
style::stylesheets::impl$0::clone
(2.96%)
Uplifts and Backouts
Bug
Component
Summary
138.0b2
4 bugs uplifted
Show crashes
Hide crashes
Show bug fixes
Hide bug fixes
OOM | small
(18.04%)
Known top crash
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::AutoEnterOOMUnsafeRegion::crash | js::gc::AllocateTenuredCellInGC
(14.37%)
Top crash
1472062
XREMain::XRE_main
(4.59%)
1909700
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::gc::TraceEdgeInternal
(3.67%)
1472062
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::AutoEnterOOMUnsafeRegion::crash | js::Nursery::maybeMoveRawBufferOnPromotion
(2.14%)
1472062
mozilla::Omnijar::Init
(1.83%)
js::InternalBarrierMethods<T>::isMarkable
(1.53%)
1932424
Uplifts and Backouts
Bug
Component
Summary
1941759
General
mach ide vscode doesn't support extended JSON syntax
1956046
Widget: Gtk
[cinnamon] Window snapping issue in Nightly (with Mint-L themes)
1956848
Machine Learning
Enable ML Engine by default
1956862
Experimentation and Telemetry
Add Telemetry for the Always Request Desktop Site under Settings > Site Settings
138.0b3
14 bugs uplifted
Show crashes
Hide crashes
Show bug fixes
Hide bug fixes
OOM | small
(14.42%)
Known top crash
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::AutoEnterOOMUnsafeRegion::crash | js::gc::AllocateTenuredCellInGC
(10.48%)
Top crash
1472062
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::gc::TraceEdgeInternal
(5.19%)
1472062
<unknown in nvwgf2umx.dll> | NDXGI::CDevice::RotateResourceIdentities
(4.15%)
nsGlobalWindowInner::ClearDocumentDependentSlots
(2.28%)
1803675
mozilla::RestyleManager::ElementStateChanged
(2.18%)
1936213
nsFind::FindFromRangeBoundaries
(2.18%)
1949877
Uplifts and Backouts
Bug
Component
Summary
1931562
Messaging System
End/close current Review Checker microsurvey
1952530
Tabbed Browser
Overlapping pinned tabs
1953664
Nimbus Desktop Client
Intermittent toolkit/components/nimbus/test/browser/browser_experimentapi_child.js | Uncaught exception in test bound testGetExperimentFromChildExistingEnrollment - at chrome://mochitests/content/browser/toolkit/components/nimbus/test/browser/
1954772
Networking
Crash [@ CanSend]
1956029
Tabbed Browser
The suggested Tabs panel does not have a scroll bar and the Cancel and Done buttons are not visible with a lot of tab suggestions
1957050
WebDriver BiDi
[Late Beta] Perma webdriver/tests/bidi/network/continue_with_auth/action.py / continue_response/credentials.py | test_provideCredentials - asyncio.exceptions.CancelledError - when Gecko 138 switches to beta on 2025-04-11
1957097
Tabbed Browser
Add telemetry for Smart Tab Group Name for empty model suggestion
1957228
Upstream Synchronization
perma toolkit/components/telemetry/dap/tests/xpcshell/test_dap.js | xpcshell return code: 0
1957545
JavaScript: WebAssembly
Assertion failure: cx->isExceptionPending() || cx->isPropagatingForcedReturn() || cx->hadUncatchableException(), at vm/Interpreter.cpp:401
1957607
DOM: Performance APIs
Cast to MouseEvent instead of PointerEvent during interactionId computation
1957623
Privacy: Anti-Tracking
Fix possible crash reasons for user-char collection
1957697
General
Toolbar is show as fixed when a11y is not enabled.
1957709
Privacy: Anti-Tracking
CHIPS needs its own Nimbus feature because of the bus factor of the networking feature
1956153
N/A
N/A
138.0b4
21 bugs uplifted
Show crashes
Hide crashes
Show bug fixes
Hide bug fixes
OOM | small
(13.62%)
Known top crash
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::AutoEnterOOMUnsafeRegion::crash | js::gc::AllocateTenuredCellInGC
(13.23%)
Top crash
1472062
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::gc::TraceEdgeInternal
(4.67%)
1472062
mozilla::RestyleManager::ElementStateChanged
(2.40%)
1936213
js::gc::detail::ChunkPtrHasStoreBuffer
(1.75%)
1940438
nsFind::FindFromRangeBoundaries
(1.40%)
1949877
msmpeg2vdec.dll | wmf::CreateMFT
(1.27%)
Uplifts and Backouts
Bug
Component
Summary
1951148
Machine Learning
add metrics and events related to link preview feature usage
1953399
Tabbed Browser
Firefox View page is suggested for smart tabs groups
1955095
Machine Learning
update error state card for link preview
1955469
Messaging System
[Spike] Investigate suppressing the Windows set default guidance notification toast via messaging system action
1955955
Tabbed Browser
Suggested Tabs are duplicated if the onboarding process is interrupted
1956215
Settings UI
The Manage Settings Option from the Callout 3 does not redirect the user to the correct option in about:preferences
1956499
Widget
15.05 - 6.35% ts_paint / startup_about_home_paint_cached + 13 more (Linux) regression on Sat March 22 2025
1956624
Sidebar
Expand on hover not working as expected if window is not foregrounded
1956909
Sidebar
Sidebar expand on hover jumpy after browser close / reopen
1957166
Widget
GTK theme changes now can get broadcasted via dbus.
1957393
Sidebar
The checkmark for enabling/disabling "Expand sidebar on hover" is not correctly displayed in the Customize Sidebar panel
1957409
Tabbed Browser
Tab group lines with collapsed sidebar have become harder to see, blending into window edge with contrasting theme and window background
1957418
Data Loss Prevention
Two final actions are displayed inside the DLP Agent on one clipboard paste
1957507
Machine Learning
"Foxfooding feedback" for link previews wants better link and/or copy
1957612
Machine Learning
Link Preview can no longer generate key points from reader view content
1957777
Tabbed Browser
STG - highlight name field when label is suggested
1957902
Data Loss Prevention
The notification that Firefox is closed during scanning is no longer displayed
1958112
Other
Crash in [@ chromesafe64.dll | _tailMerge_d3dcompiler_47.dll | chromesafe64.dll | NS_TableDrivenQI]
1958222
Widget: Win32
Firefox incorrectly treats folder shortcuts as files when attaching them in webmail.
1958267
Widget: Gtk
Crash in [@ settings_changed_cb]
1958293
Layout
Crash in [@ mozilla::css::SheetLoadData::VerifySheetReadyToParse]
138.0b5
27 bugs uplifted
Show crashes
Hide crashes
Show bug fixes
Hide bug fixes
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::AutoEnterOOMUnsafeRegion::crash | js::gc::AllocateTenuredCellInGC
(15.19%)
Top crash
1472062
OOM | small
(13.63%)
Known top crash
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::gc::TraceEdgeInternal
(5.89%)
1472062
js::gc::detail::ChunkPtrHasStoreBuffer
(1.71%)
1940438
js::gc::HeaderWord::get
(1.61%)
1948635
nsFind::FindFromRangeBoundaries
(1.51%)
1949877
mozilla::dom::quota::QuotaManager::Shutdown::<T>::operator()
(1.41%)
1872960
Uplifts and Backouts
Bug
Component
Summary
1657591
Security: PSM
remember client auth decisions on a per-session basis
1824697
Widget: Win32
Crash in [@ nsObserverService::EnsureValidCall | nsObserverService::RemoveObserver | LocalesChangedObserver::Unregister]
1928382
Networking: Cache
Crash in [@ mozilla::net::CacheFileMetadata::GetElement]
1938430
Tabbed Browser
Record telemetry event when deleting a tab group
1947678
WebDriver BiDi
"webExtenstion.install" should install web extensions temporary by default and allow a permanent installation as well.
1949912
Sidebar
Create a Nimbus variable for controlling whether the sidebar is visible or hidden for horizontal tab users
1950468
Messaging System
Tab Groups - New Trigger Request
1953015
Crash Reporting
Perma Win MinGW ld.lld: error: undefined symbol: _ProcessPrng@8 | single tracking bug
1953857
Messaging System
Add support for picker style tiles in the AboutWelcome MultiSelect component
1954990
Sidebar
Having too many pinned tabs will reduce or hide the normal tabs area
1955265
Sidebar
The option to hide sidebar tabs and sidebar is available to be used even if expand on hover is active
1956314
Tabbed Browser
Container tabs hairline not visible in collapsed sidebar
1957305
Machine Learning
[linkPreview] Use blocklist for AI generation
1957333
Netmonitor
HTML preview of response is affected by the netmonitor's CSP
1957354
web-platform-tests
Update web-platform-tests to 5903faa96e872e304d9c90b7c7bc98c3512fca99
1957434
Tabbed Browser
Dragging tab to the end of the tab strip briefly animates it from the original position when dropping
1957554
Netmonitor
Net monitor path column is not sortable
1957678
DOM: postMessage
Checking for duplicates in the transferables list is quadratic
1957956
DOM: Core & HTML
`preventDefault` behavior changed for radio inputs
1957998
Mach Core
Running ./mach storybook no longer works
1958036
Audio/Video
Regression in 1850615 breaks V4L2 h264 decoding
1958123
New Tab Page
Add missing telemetry events to the new ads context menu
1958196
Startup and Profile System
Visibility issues in profiles using the System theme after an OS theme change
1958862
Search
[Trending Searches] Enable secret settings in beta and release
1956698
N/A
N/A
1958411
N/A
N/A
1958049
N/A
N/A
138.0b6
23 bugs uplifted
Show crashes
Hide crashes
Show bug fixes
Hide bug fixes
OOM | small
(13.10%)
Known top crash
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::AutoEnterOOMUnsafeRegion::crash | js::gc::AllocateTenuredCellInGC
(11.84%)
Top crash
1472062
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | mozilla::BitSet<T>::FindNext
(3.22%)
1949316
js::gc::detail::ChunkPtrHasStoreBuffer
(2.59%)
1940438
js::gc::HeaderWord::get
(1.84%)
1948635
ComObject<T>::Release
(1.67%)
mozilla::RestyleManager::ElementStateChanged
(1.67%)
1936213
Uplifts and Backouts
Bug
Component
Summary
1947470
Panning and Zooming
hdfcbank.com - When typing in the support chat, it gets scrolled to the top
1952563
PDF Viewer
Blue 'Undo' button over blue snackbar background fails contrast
1954474
General
[Dev Tools] Error: Protocol error (NS_ERROR_XPC_BAD_CONVERT_NATIVE); when opening the dev tools at https://openguessr.com/
1956330
Sidebar
Extension sidebar panel broken after reopening the new sidebar while the extension panel was still the one selected
1957723
Tabbed Browser
The index property is not respected when using tabs.create() inside a tab group
1957907
New Tab Page
The Contextual menu button of the Billboard and Leaderboard banners doesn’t have a hover effect
1957924
Startup and Profile System
Sync new profile group ID across profiles
1957950
Search
Telemetry to Measure Suggestion Network Traffic Performance
1958192
Sidebar
Attention dot is not visible while expanding the sidebar by hover
1958316
Messaging System
Support setting a pref to a string of the current timestamp via Special Message Action
1958596
Widget: Gtk
GTK tooltip background color applies wrongly when switching system dark/light color scheme with webextension theme
1958631
Widget: Win32
[windows] hover tooltips flicker in some cases
1958819
New Tab Page
The “Manage more settings” link from the Customization Panel is not displayed in blue as expected
1958822
New Tab Page
The custom wallpaper message is not blocked after interacting with it
1958907
Tabbed Browser
Improve Precision for AI Tab Suggestions
1958972
Messaging System
Add dismissable property configurable for infobars
1959251
Web Painting
Firefox no longer responds to clicks in the HTML5 video player
1959402
Tabbed Browser
Smart tab grouping suggested tabs don't suggest pages with same URL and text
1959438
Tabbed Browser
Duplicating a tab just to the left of a tab group causes the tab to appear overtop of the tab label
1959683
Task Configuration
periodic updates task hanging due to new search-config-icon files
1959827
Audio/Video: Playback
Revert PlayReady CDM filtering back to an allow list by default (release only)
1915280
N/A
N/A
1958259
N/A
N/A
138.0b7
16 bugs uplifted
Show crashes
Hide crashes
Show bug fixes
Hide bug fixes
mozilla::dom::ServiceWorkerRegistrar::GetShutdownPhase
(24.32%)
Top crash
1928888
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | js::AutoEnterOOMUnsafeRegion::crash | js::gc::AllocateTenuredCellInGC
(10.81%)
Top crash
1472062
AsyncShutdownTimeout | quit-application-granted | XPIProvider shutdown
(5.41%)
OOM | large | mozilla::JSHolderMap::Put
(5.41%)
1892171
OOM | unknown | js::AutoEnterOOMUnsafeRegion::crash_impl | mozilla::BitSet<T>::FindNext
(5.41%)
1949316
FindNextFileNameW
(2.70%)
OOM | large | alloc::raw_vec::handle_error
(2.70%)
1906769
Uplifts and Backouts
Bug
Component
Summary
1885743
Audio/Video: Playback
Crash in [@ mozilla::MFCDMSession::Create] with canalplus.com
1938425
Tabbed Browser
Record telemetry event when reopening a saved tab group
1951249
Widget: Gtk
[Gnome/Wayland][VSync] Painting stops every now and then on Linux
1957749
Security: Process Sandboxing
SandboxBroker thread stack and TCB are leaked if the broker holds the last reference to itself
1957892
Widget: Gtk
26.06% glterrain (Linux) regression on Tue March 25 2025
1958510
New Tab Page
The Wallpaper styles are not displayed in the Personalization Menu when enabling the “customWallpaper” feature configuration via Nimbus on the Stage server
1958817
New Tab Page
The wallpaper styles from the Wallpaper section cannot be accessed using the keyboard navigation except the “Abstract” one
1959121
Sidebar
[legacy sidebar] Sidebar does not remember last used if closed it with close x button
1959163
Search
Update search-config-icons dumps
1959409
Graphics: Canvas2D
CanvasRenderingContext2D forgets clip-path occasionally
1959492
Application Update
Disable the "Bypassing Updates" feature
1959630
Widget: Gtk
DBUS accent color only gets applied after a theme change.
1959815
Graphics: Canvas2D
Last clearRect region is used when setting width and height
1959902
Sidebar
The "x" (Close) button in the new sidebar cannot be reached when navigating with the keyboard in some panels
1959981
Tabbed Browser
Perma Late Beta TEST-UNEXPECTED-FAIL | browser/components/tabbrowser/test/browser/tabs/browser_tab_groups_telemetry.js | Reopen group action is present in results - false == true - when Gecko 139 switches to Late Beta on 2025-05-09
1959367
N/A
N/A
138.0b8
9 bugs uplifted
(upcoming beta, not shipped yet)
Show bug fixes
Hide bug fixes
Uplifts and Backouts
Bug
Component
Summary
1938424
Tabbed Browser
Record telemetry event when adding tabs to a tab group
1941491
Toolbars and Customization
Intermittent browser/components/customizableui/test/marionette/test_assert_no_toolbar_changes.py | single tracking bug
1946738
PDF Viewer
Enable signing in a PDF in Release
1959562
L10N
Perma lint android-l10n /builds/worker/checkouts/gecko/mobile/android/android-components/components/compose/base/src/main/res/values-cy/strings.xml:0 | No matching license strings found in tools/lint/license/valid-licenses.txt (license)
1959713
General
Implement tabs.Tab.groupId
1959714
General
Implement tabs.group() and tabs.ungroup()
1959715
General
Support groupId in tabs.query
1959716
General
Implement groupId in tabs.onUpdated
1959730
Tabbed Browser
TabMove event not dispatched for tabs when moving a group within the tab strip