FAILED_PRECONDITION: duplicate files

[luxe]

Many of our schedulers are producing this error:

ERROR: <path>/BUILD:39:1: C++ compilation of rule '<target>' failed (Exit 34): java.io.IOException: com.google.devtools.build.lib.remote.ExecutionStatusException: FAILED_PRECONDITION: Action 47a406c798e283a9bc73cd37f2802fd96cd4a4407b644bae5d5e3d599050330e/143 is invalid: One of the input `Directory` has multiple entries with the same file name. This will also occur if the worker filesystem considers two names to be the same, such as two names that vary only by case on a case-insensitive filesystem, or two names with the same normalized form on a filesystem that performs Unicode normalization on filenames.; One of the input `Directory` has multiple entries with the same file name. This will also occur if the worker filesystem considers two names to be the same, such as two names that vary only by case on a case-insensitive filesystem, or two names with the same normalized form on a filesystem that performs Unicode normalization on filenames.; One of the input `Directory` has multiple entries with the same file name. This will also occur if the worker filesystem considers two names to be the same, such as two names that vary only by case on a case-insensitive filesystem, or two names with the same normalized form on a filesystem that performs Unicode normalization on filenames. ...
--
  | at com.google.devtools.build.lib.remote.GrpcRemoteExecutor.executeRemotely(GrpcRemoteExecutor.java:192)
  | at com.google.devtools.build.lib.remote.RemoteSpawnRunner.lambda$exec$0(RemoteSpawnRunner.java:324)
  | at com.google.devtools.build.lib.remote.Retrier.execute(Retrier.java:237)
  | at com.google.devtools.build.lib.remote.RemoteRetrier.execute(RemoteRetrier.java:116)
  | at com.google.devtools.build.lib.remote.RemoteSpawnRunner.exec(RemoteSpawnRunner.java:304)
  | at com.google.devtools.build.lib.exec.SpawnRunner.execAsync(SpawnRunner.java:238)
  | at com.google.devtools.build.lib.exec.AbstractSpawnStrategy.exec(AbstractSpawnStrategy.java:126)
  | at com.google.devtools.build.lib.exec.AbstractSpawnStrategy.exec(AbstractSpawnStrategy.java:96)
  | at com.google.devtools.build.lib.actions.SpawnStrategy.beginExecution(SpawnStrategy.java:39)
  | at com.google.devtools.build.lib.exec.ProxySpawnActionContext.beginExecution(ProxySpawnActionContext.java:60)
  | at com.google.devtools.build.lib.rules.cpp.CppCompileAction.beginExecution(CppCompileAction.java:1402)
  | at com.google.devtools.build.lib.actions.Action.execute(Action.java:124)
  | at com.google.devtools.build.lib.skyframe.SkyframeActionExecutor$4.execute(SkyframeActionExecutor.java:961)
  | at com.google.devtools.build.lib.skyframe.SkyframeActionExecutor$ActionRunner.continueAction(SkyframeActionExecutor.java:1109)
  | at com.google.devtools.build.lib.skyframe.SkyframeActionExecutor$ActionRunner.run(SkyframeActionExecutor.java:1080)
  | at com.google.devtools.build.lib.skyframe.ActionExecutionState.runStateMachine(ActionExecutionState.java:137)
  | at com.google.devtools.build.lib.skyframe.ActionExecutionState.getResultOrDependOnFuture(ActionExecutionState.java:80)
  | at com.google.devtools.build.lib.skyframe.SkyframeActionExecutor.executeAction(SkyframeActionExecutor.java:601)
  | at com.google.devtools.build.lib.skyframe.ActionExecutionFunction.checkCacheAndExecuteIfNeeded(ActionExecutionFunction.java:907)
  | at com.google.devtools.build.lib.skyframe.ActionExecutionFunction.compute(ActionExecutionFunction.java:297)
  | at com.google.devtools.build.skyframe.AbstractParallelEvaluator$Evaluate.run(AbstractParallelEvaluator.java:438)
  | at com.google.devtools.build.lib.concurrent.AbstractQueueVisitor$WrappedRunnable.run(AbstractQueueVisitor.java:399)
  | at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
  | at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
  | at java.base/java.lang.Thread.run(Unknown Source)

Find out why this is happening. See if error message can be extended to produce the actual filename that has the clash or if that doesn't make sense since they are hashed names.

[werkt]

bf-cat ... Action 47a406c798e283a9bc73cd37f2802fd96cd4a4407b644bae5d5e3d599050330e/143 -> Input Root Digest
bf-cat ... TreeLayout <Input Root Digest> -> Scan this list and find the directory with the repeated filename

[luxe]

I'm not seeing any duplicates in the TreeLayout. I shouldn't post the output as it contains the majority of our tree. Maybe I can re-serialize the TreeLayout and run it though buildfarm's validation to see if it still fails.

[werkt]

bazelbuild/bazel#12564 over on bazel will drastically improve this output on the client side, which is where the output itself comes from. There will need to be changes on the buildfarm side to clean up some of the logging, and I want to add configurable help messages for the client to take action - these can provide brief instructions and an url to go to for more information, and even prepopulate content with the error information