06 Mar 2026
Planet Mozilla
The Mozilla Blog: Hardening Firefox with Anthropic’s Red Team
For more than two decades, Firefox has been one of the most scrutinized and security-hardened codebases on the web. Open source means our code is visible, reviewable, and continuously stress-tested by a global community.
A few weeks ago, Anthropic's Frontier Red Team approached us with results from a new AI-assisted vulnerability-detection method that surfaced more than a dozen verifiable security bugs, with reproducible tests. Our engineers validated the findings and landed fixes ahead of the recently shipped Firefox 148.
For users, that means better security and stability in Firefox. Adding new techniques to our security toolkit helps us identify and fix vulnerabilities before they can be exploited in the wild.
An emerging technique, pressure-tested by Firefox engineers
AI-assisted bug reports have a mixed track record, and skepticism is earned. Too many submissions have meant false positives and an extra burden for open source projects. What we received from the Frontier Red Team at Anthropic was different.
Anthropic's team got in touch with Firefox engineers after using Claude to identify security bugs in our JavaScript engine. Critically, their bug reports included minimal test cases that allowed our security team to quickly verify and reproduce each issue.
Within hours, our platform engineers began landing fixes, and we kicked off a tight collaboration with Anthropic to apply the same technique across the rest of the browser codebase. In total, we discovered 14 high-severity bugs and issued 22 CVEs as a result of this work. All of these bugs are now fixed in the latest version of the browser.
In addition to the 22 security-sensitive bugs, Anthropic discovered 90 other bugs, most of which are now fixed. A number of the lower-severity findings were assertion failures, which overlapped with issues traditionally found through fuzzing, an automated testing technique that feeds software huge numbers of unexpected inputs to trigger crashes and bugs. However, the model also identified distinct classes of logic errors that fuzzers had not previously uncovered.
Anthropic has also published a technical write-up of their research process and findings, which we invite you to read here.
The scale of findings reflects the power of combining rigorous engineering with new analysis tools for continuous improvement. We view this as clear evidence that large-scale, AI-assisted analysis is a powerful new addition in security engineers' toolbox. Firefox has undergone some of the most extensive fuzzing, static analysis, and regular security review over decades. Despite this, the model was able to reveal many previously unknown bugs. This is analogous to the early days of fuzzing; there is likely a substantial backlog of now-discoverable bugs across widely deployed software.
Firefox was not selected at random. It was chosen because it is a widely deployed and deeply scrutinized open source project - an ideal proving ground for a new class of defensive tools. Mozilla has historically led in deploying advanced security techniques to protect Firefox users. In that same spirit, our team has already started integrating AI-assisted analysis into our internal security workflows to find and fix vulnerabilities before attackers do.
Building in the open for users
Firefox has always championed building publicly and working with our community to build a browser that puts users first. This work reflects Mozilla's long-standing commitment to applying emerging technologies thoughtfully and in service of user security.
The Frontier Red Team at Anthropic showed what collaboration in this space looks like in practice: responsibly disclosing bugs to maintainers, and working together to make them as actionable as possible. As AI accelerates both attacks and defenses, Mozilla will continue investing in the tools, processes, and collaborations that ensure Firefox keeps getting stronger and that users stay protected.
The post Hardening Firefox with Anthropic's Red Team appeared first on The Mozilla Blog.
06 Mar 2026 10:30am GMT
Jonathan Almeida: My Firefox for Android local build environment
The Firefox for Android app has always had a complicated build process - we're cramping a complex cross-platform browser engine and all the related components that make it work on Android into one package. In its current form, it lives in the Firefox mono-repo at mozilla-central (now mozilla-firefox using the git repository).
I wanted to document my "artifact-mode" environment here since it's worked quite successfully for me for many years with minor changes.
NOTE: After a fresh clone of the mono-repo, don't forget to first run and follow the prompts of
./mach bootstrap.
mozconfig
My mozconfig below is enabled for artifact mode, but occasionally I switch between various configurations. You can see those commented out, with these few extra notes:
- I like to separate out my objdirs to avoid cache pollution between the different build types. I think you can get away without needing to specify this and an objdir for your build type and arch will be generated.
sccachespeeds up the native portion of full builds after the first slow one, but it's a hit or miss if you fetch from the remote repository but don't need to rebuild as often.- I don't care to manually run the clobber step, and I don't truly appreciate why that isn't always automatically done.
- Emilio's mozconfig manager looks like a better solution, however my needs are very simple.
# Build GeckoView/Firefox for Android:
ac_add_options --enable-application=mobile/android
# Targeting the following architecture.
# For regular phones, no --target is needed.
# For x86 emulators (and x86 devices, which are uncommon):
# ac_add_options --target=i686
# For newer phones or Apple silicon
ac_add_options --target=aarch64
# For x86_64 emulators (and x86_64 devices, which are even less common):
# ac_add_options --target=x86_64
# sccache will significantly speed up your builds by caching
# compilation results. The Firefox build system will download
# sccache automatically.
# This only works for non-artifact builds.
#ac_add_options --with-ccache=sccache
# Enable artifact builds; manager-mode.
ac_add_options --enable-artifact-builds
# Write build artifacts to..
## Full build dir
#mk_add_options MOZ_OBJDIR=./objdir-droid
#mk_add_options MOZ_OBJDIR=./objdir-desktop
## Artifact builds
mk_add_options MOZ_OBJDIR=./objdir-frontend
# Automatic clobbering; don't ask me.
mk_add_options AUTOCLOBBER=1
JAVA_HOME
Sometimes you might find yourself needing to run a (non-mach) command in the terminal. Those typically will need to invoke some parts of gradle for an Android build, so it's best to make sure those are using the same JDK as the bootstrapped one in the mono-repo. This avoids weird build errors where something that compiles in one place isn't working in another (like Android Studio).
The location for the JDKs are typically in ~/.mozbuild/jdk/, and if you've between around for ~6 months you end up with multiple versions after every JDK bump:
$ ls -l ~/.mozbuild/jdk/
drwxr-xr-x@ - jalmeida 15 Apr 2025 jdk-17.0.15+6
drwxr-xr-x@ - jalmeida 15 Jul 2025 jdk-17.0.16+8
drwxr-xr-x@ - jalmeida 21 Oct 2025 jdk-17.0.17+10
drwxr-xr-x@ - jalmeida 20 Jan 09:00 jdk-17.0.18+8
drwxr-xr-x@ - jalmeida 26 Feb 15:04 mozboot
You can find some way to point your latest JDK to one location or you can be lazy like me and pick the latest version to assign as your JAVA_HOME property by adding this to your shell's RC file:
export JAVA_HOME="$(ls -1dr -- $HOME/.mozbuild/jdk/jdk-* | head -n 1)/Contents/Home"
Android Studio
Similarly for Android Studio, let's do the same so that environment is identical. Head to, Settings | Build, Execution, Deployment | Build Tools | Gradle, and ensure that "Gradle JDK" path is set to JAVA_HOME.
Lately, the default seems to be for it to follow GRADLE_LOCAL_JAVA_HOME which is a property we can't easily override, so we have to manually set this ourselves.
Debugging
This section is for miscellaneous build error situations that come-up, but assuming mach build work and there are no known Android build changes, my solution has typically always been the same.
For example, the other day I fetched another engineers patch to test out locally1 as part of reviewing it where I faced the error message below:
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':components:feature-pwa:compileDebugKotlin'.
> A failure occurred while executing org.jetbrains.kotlin.compilerRunner.GradleCompilerRunnerWithWorkers$GradleKotlinCompilerWorkAction
> Internal compiler error. See log for more details
* Try:
> Run with --info or --debug option to get more log output.
> Run with --scan to generate a Build Scan (powered by Develocity).
> Get more help at https://help.gradle.org.
* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':components:feature-pwa:compileDebugKotlin'.
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.lambda$executeIfValid$1(ExecuteActionsTaskExecuter.java:135)
at org.gradle.internal.Try$Failure.ifSuccessfulOrElse(Try.java:288)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:133)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:121)
at org.gradle.api.internal.tasks.execution.ProblemsTaskPathTrackingTaskExecuter.execute(ProblemsTaskPathTrackingTaskExecuter.java:41)
at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46)
at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:51)
at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:74)
at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77)
at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55)
at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:209)
at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:166)
at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
at org.gradle.execution.plan.DefaultNodeExecutor.executeLocalTaskNode(DefaultNodeExecutor.java:55)
at org.gradle.execution.plan.DefaultNodeExecutor.execute(DefaultNodeExecutor.java:34)
at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:355)
at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:343)
at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.lambda$execute$0(DefaultTaskExecutionGraph.java:339)
at org.gradle.internal.operations.CurrentBuildOperationRef.with(CurrentBuildOperationRef.java:84)
at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:339)
at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:328)
at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:459)
at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:376)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
at org.gradle.internal.concurrent.AbstractManagedExecutor$1.run(AbstractManagedExecutor.java:47)
Caused by: org.gradle.workers.internal.DefaultWorkerExecutor$WorkExecutionException: A failure occurred while executing org.jetbrains.kotlin.compilerRunner.GradleCompilerRunnerWithWorkers$GradleKotlinCompilerWorkAction
at org.gradle.workers.internal.DefaultWorkerExecutor$WorkItemExecution.waitForCompletion(DefaultWorkerExecutor.java:289)
at org.gradle.internal.work.DefaultAsyncWorkTracker.lambda$waitForItemsAndGatherFailures$2(DefaultAsyncWorkTracker.java:130)
at org.gradle.internal.Factories$1.create(Factories.java:33)
at org.gradle.internal.work.DefaultWorkerLeaseService.lambda$withoutLocks$2(DefaultWorkerLeaseService.java:344)
at org.gradle.internal.work.ResourceLockStatistics$1.measure(ResourceLockStatistics.java:42)
at org.gradle.internal.work.DefaultWorkerLeaseService.withoutLocks(DefaultWorkerLeaseService.java:342)
at org.gradle.internal.work.DefaultWorkerLeaseService.withoutLocks(DefaultWorkerLeaseService.java:326)
at org.gradle.internal.work.DefaultWorkerLeaseService.withoutLock(DefaultWorkerLeaseService.java:331)
at org.gradle.internal.work.DefaultAsyncWorkTracker.waitForItemsAndGatherFailures(DefaultAsyncWorkTracker.java:126)
at org.gradle.internal.work.DefaultAsyncWorkTracker.waitForItemsAndGatherFailures(DefaultAsyncWorkTracker.java:92)
at org.gradle.internal.work.DefaultAsyncWorkTracker.waitForAll(DefaultAsyncWorkTracker.java:78)
at org.gradle.internal.work.DefaultAsyncWorkTracker.waitForCompletion(DefaultAsyncWorkTracker.java:66)
at org.gradle.api.internal.tasks.execution.TaskExecution$3.run(TaskExecution.java:260)
at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:29)
at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:26)
at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:166)
at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
at org.gradle.internal.operations.DefaultBuildOperationRunner.run(DefaultBuildOperationRunner.java:47)
at org.gradle.api.internal.tasks.execution.TaskExecution.executeAction(TaskExecution.java:237)
at org.gradle.api.internal.tasks.execution.TaskExecution.executeActions(TaskExecution.java:220)
at org.gradle.api.internal.tasks.execution.TaskExecution.executeWithPreviousOutputFiles(TaskExecution.java:203)
at org.gradle.api.internal.tasks.execution.TaskExecution.execute(TaskExecution.java:170)
at org.gradle.internal.execution.steps.ExecuteStep.executeInternal(ExecuteStep.java:105)
at org.gradle.internal.execution.steps.ExecuteStep.access$000(ExecuteStep.java:44)
at org.gradle.internal.execution.steps.ExecuteStep$1.call(ExecuteStep.java:59)
at org.gradle.internal.execution.steps.ExecuteStep$1.call(ExecuteStep.java:56)
at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:209)
at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:166)
at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:56)
at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:44)
at org.gradle.internal.execution.steps.CancelExecutionStep.execute(CancelExecutionStep.java:42)
at org.gradle.internal.execution.steps.TimeoutStep.executeWithoutTimeout(TimeoutStep.java:75)
at org.gradle.internal.execution.steps.TimeoutStep.execute(TimeoutStep.java:55)
at org.gradle.internal.execution.steps.PreCreateOutputParentsStep.execute(PreCreateOutputParentsStep.java:50)
at org.gradle.internal.execution.steps.PreCreateOutputParentsStep.execute(PreCreateOutputParentsStep.java:28)
at org.gradle.internal.execution.steps.RemovePreviousOutputsStep.execute(RemovePreviousOutputsStep.java:68)
at org.gradle.internal.execution.steps.RemovePreviousOutputsStep.execute(RemovePreviousOutputsStep.java:38)
at org.gradle.internal.execution.steps.BroadcastChangingOutputsStep.execute(BroadcastChangingOutputsStep.java:61)
at org.gradle.internal.execution.steps.BroadcastChangingOutputsStep.execute(BroadcastChangingOutputsStep.java:26)
at org.gradle.internal.execution.steps.CaptureOutputsAfterExecutionStep.execute(CaptureOutputsAfterExecutionStep.java:69)
at org.gradle.internal.execution.steps.CaptureOutputsAfterExecutionStep.execute(CaptureOutputsAfterExecutionStep.java:46)
at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:39)
at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:28)
at org.gradle.internal.execution.steps.BuildCacheStep.executeWithoutCache(BuildCacheStep.java:189)
at org.gradle.internal.execution.steps.BuildCacheStep.lambda$execute$1(BuildCacheStep.java:75)
at org.gradle.internal.Either$Right.fold(Either.java:176)
at org.gradle.internal.execution.caching.CachingState.fold(CachingState.java:62)
at org.gradle.internal.execution.steps.BuildCacheStep.execute(BuildCacheStep.java:73)
at org.gradle.internal.execution.steps.BuildCacheStep.execute(BuildCacheStep.java:48)
at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:46)
at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:35)
at org.gradle.internal.execution.steps.SkipUpToDateStep.executeBecause(SkipUpToDateStep.java:75)
at org.gradle.internal.execution.steps.SkipUpToDateStep.lambda$execute$2(SkipUpToDateStep.java:53)
at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:53)
at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:35)
at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:37)
at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:27)
at org.gradle.internal.execution.steps.ResolveIncrementalCachingStateStep.executeDelegate(ResolveIncrementalCachingStateStep.java:49)
at org.gradle.internal.execution.steps.ResolveIncrementalCachingStateStep.executeDelegate(ResolveIncrementalCachingStateStep.java:27)
at org.gradle.internal.execution.steps.AbstractResolveCachingStateStep.execute(AbstractResolveCachingStateStep.java:71)
at org.gradle.internal.execution.steps.AbstractResolveCachingStateStep.execute(AbstractResolveCachingStateStep.java:39)
at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:64)
at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:35)
at org.gradle.internal.execution.steps.ValidateStep.execute(ValidateStep.java:62)
at org.gradle.internal.execution.steps.ValidateStep.execute(ValidateStep.java:40)
at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.execute(AbstractCaptureStateBeforeExecutionStep.java:76)
at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.execute(AbstractCaptureStateBeforeExecutionStep.java:45)
at org.gradle.internal.execution.steps.AbstractSkipEmptyWorkStep.executeWithNonEmptySources(AbstractSkipEmptyWorkStep.java:136)
at org.gradle.internal.execution.steps.AbstractSkipEmptyWorkStep.execute(AbstractSkipEmptyWorkStep.java:66)
at org.gradle.internal.execution.steps.AbstractSkipEmptyWorkStep.execute(AbstractSkipEmptyWorkStep.java:38)
at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsStartedStep.execute(MarkSnapshottingInputsStartedStep.java:38)
at org.gradle.internal.execution.steps.LoadPreviousExecutionStateStep.execute(LoadPreviousExecutionStateStep.java:36)
at org.gradle.internal.execution.steps.LoadPreviousExecutionStateStep.execute(LoadPreviousExecutionStateStep.java:23)
at org.gradle.internal.execution.steps.HandleStaleOutputsStep.execute(HandleStaleOutputsStep.java:75)
at org.gradle.internal.execution.steps.HandleStaleOutputsStep.execute(HandleStaleOutputsStep.java:41)
at org.gradle.internal.execution.steps.AssignMutableWorkspaceStep.lambda$execute$0(AssignMutableWorkspaceStep.java:35)
at org.gradle.api.internal.tasks.execution.TaskExecution$4.withWorkspace(TaskExecution.java:297)
at org.gradle.internal.execution.steps.AssignMutableWorkspaceStep.execute(AssignMutableWorkspaceStep.java:31)
at org.gradle.internal.execution.steps.AssignMutableWorkspaceStep.execute(AssignMutableWorkspaceStep.java:22)
at org.gradle.internal.execution.steps.ChoosePipelineStep.execute(ChoosePipelineStep.java:40)
at org.gradle.internal.execution.steps.ChoosePipelineStep.execute(ChoosePipelineStep.java:23)
at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.lambda$execute$2(ExecuteWorkBuildOperationFiringStep.java:67)
at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.execute(ExecuteWorkBuildOperationFiringStep.java:67)
at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.execute(ExecuteWorkBuildOperationFiringStep.java:39)
at org.gradle.internal.execution.steps.IdentityCacheStep.execute(IdentityCacheStep.java:46)
at org.gradle.internal.execution.steps.IdentityCacheStep.execute(IdentityCacheStep.java:34)
at org.gradle.internal.execution.steps.IdentifyStep.execute(IdentifyStep.java:44)
at org.gradle.internal.execution.steps.IdentifyStep.execute(IdentifyStep.java:31)
at org.gradle.internal.execution.impl.DefaultExecutionEngine$1.execute(DefaultExecutionEngine.java:64)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:132)
... 30 more
Caused by: org.jetbrains.kotlin.gradle.tasks.FailedCompilationException: Internal compiler error. See log for more details
at org.jetbrains.kotlin.gradle.tasks.TasksUtilsKt.throwExceptionIfCompilationFailed(tasksUtils.kt:22)
at org.jetbrains.kotlin.compilerRunner.GradleKotlinCompilerWork.run(GradleKotlinCompilerWork.kt:112)
at org.jetbrains.kotlin.compilerRunner.GradleCompilerRunnerWithWorkers$GradleKotlinCompilerWorkAction.execute(GradleCompilerRunnerWithWorkers.kt:75)
at org.gradle.workers.internal.DefaultWorkerServer.execute(DefaultWorkerServer.java:68)
at org.gradle.workers.internal.NoIsolationWorkerFactory$1$1.create(NoIsolationWorkerFactory.java:64)
at org.gradle.workers.internal.NoIsolationWorkerFactory$1$1.create(NoIsolationWorkerFactory.java:61)
at org.gradle.internal.classloader.ClassLoaderUtils.executeInClassloader(ClassLoaderUtils.java:100)
at org.gradle.workers.internal.NoIsolationWorkerFactory$1.lambda$execute$0(NoIsolationWorkerFactory.java:61)
at org.gradle.workers.internal.AbstractWorker$1.call(AbstractWorker.java:44)
at org.gradle.workers.internal.AbstractWorker$1.call(AbstractWorker.java:41)
at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:209)
at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:166)
at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
at org.gradle.workers.internal.AbstractWorker.executeWrappedInBuildOperation(AbstractWorker.java:41)
at org.gradle.workers.internal.NoIsolationWorkerFactory$1.execute(NoIsolationWorkerFactory.java:58)
at org.gradle.workers.internal.DefaultWorkerExecutor.lambda$submitWork$0(DefaultWorkerExecutor.java:176)
at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.runExecution(DefaultConditionalExecutionQueue.java:194)
at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.access$700(DefaultConditionalExecutionQueue.java:127)
at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner$1.run(DefaultConditionalExecutionQueue.java:169)
at org.gradle.internal.Factories$1.create(Factories.java:33)
at org.gradle.internal.work.DefaultWorkerLeaseService.lambda$withLocksAcquired$0(DefaultWorkerLeaseService.java:269)
at org.gradle.internal.work.ResourceLockStatistics$1.measure(ResourceLockStatistics.java:42)
at org.gradle.internal.work.DefaultWorkerLeaseService.withLocksAcquired(DefaultWorkerLeaseService.java:267)
at org.gradle.internal.work.DefaultWorkerLeaseService.withLocks(DefaultWorkerLeaseService.java:259)
at org.gradle.internal.work.DefaultWorkerLeaseService.runAsWorkerThread(DefaultWorkerLeaseService.java:127)
at org.gradle.internal.work.DefaultWorkerLeaseService.runAsWorkerThread(DefaultWorkerLeaseService.java:132)
at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.runBatch(DefaultConditionalExecutionQueue.java:164)
at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.run(DefaultConditionalExecutionQueue.java:133)
... 2 more
The full trace was long and didn't seem related to a code failure in the module itself. So I employed the solution, which is always the same:
./mach build- In Android Studio, File > Sync Project with Gradle Files.
Yup, that's all. Very simple and boring.
With Jujutsu, this is the moz-phab command I use which has made it easier to manage review patches: moz-phab patch <patch-id> --no-branch --apply-to main@origin
06 Mar 2026 12:32am GMT
05 Mar 2026
Planet Mozilla
Firefox Tooling Announcements: MozPhab 2.9.0 Released
Issues resolved in Moz-Phab 2.9.0:
- use Lando's Mercurial patch application method
Discuss these changes in #engineering-workflow on Slack or #Conduit Matrix.
1 post - 1 participant
05 Mar 2026 9:47pm GMT