"Update settings" in a big project causes "Scanning files to index" stuck forever

Repro:

• open up a big project (somewhat a dozen of cabal packages, ~50K LOC in Haskell)
• Issue an “Update settings and restart REPLs” command

Expected: it finishes in about same time it was upon opening the project (a minute maybe).

Instead: it is stuck for tens of minutes, haven’t seen it finished without user interaction.

Closing project in that state produces following (maybe unrelated) exception:

stacktrace

java.lang.AssertionError: Already disposed: Project (Disposed) [REDACTED]
	at com.intellij.openapi.components.impl.ComponentManagerImpl.lambda$throwAlreadyDisposed$1(ComponentManagerImpl.java:245)
	at com.intellij.openapi.application.ReadAction.lambda$run$1(ReadAction.java:53)
	at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:977)
	at com.intellij.openapi.application.ReadAction.compute(ReadAction.java:57)
	at com.intellij.openapi.application.ReadAction.run(ReadAction.java:53)
	at com.intellij.openapi.components.impl.ComponentManagerImpl.throwAlreadyDisposed(ComponentManagerImpl.java:243)
	at com.intellij.openapi.components.impl.ComponentManagerImpl.getPicoContainer(ComponentManagerImpl.java:236)
	at com.intellij.openapi.components.impl.ComponentManagerImpl.getPicoContainer(ComponentManagerImpl.java:46)
	at com.intellij.openapi.components.ServiceManager.doGetService(ServiceManager.java:47)
	at com.intellij.openapi.components.ServiceManager.getService(ServiceManager.java:30)
	at com.intellij.openapi.roots.impl.libraries.ProjectLibraryTable.getInstance(ProjectLibraryTable.java:10)
	at com.intellij.openapi.roots.impl.libraries.LibraryTablesRegistrarImpl.getLibraryTable(LibraryTablesRegistrarImpl.java:41)
	at com.intellij.openapi.roots.impl.libraries.LibraryTablesRegistrarImpl.getLibraryTableByLevel(LibraryTablesRegistrarImpl.java:46)
	at com.intellij.openapi.roots.impl.LibraryOrderEntryImpl.dispose(LibraryOrderEntryImpl.java:235)
	at com.intellij.openapi.util.Disposer$1.execute(Disposer.java:48)
	at com.intellij.openapi.util.Disposer$1.execute(Disposer.java:44)
	at com.intellij.openapi.util.objectTree.ObjectTree.executeActionWithRecursiveGuard(ObjectTree.java:182)
	at com.intellij.openapi.util.objectTree.ObjectTree.executeUnregistered(ObjectTree.java:194)
	at com.intellij.openapi.util.objectTree.ObjectTree.executeAll(ObjectTree.java:147)
	at com.intellij.openapi.util.Disposer.dispose(Disposer.java:129)
	at com.intellij.openapi.util.Disposer.dispose(Disposer.java:125)
	at com.intellij.openapi.CompositeDisposable.dispose(CompositeDisposable.java:45)
	at com.intellij.openapi.util.Disposer$1.execute(Disposer.java:48)
	at com.intellij.openapi.util.Disposer$1.execute(Disposer.java:44)
	at com.intellij.openapi.util.objectTree.ObjectTree.executeActionWithRecursiveGuard(ObjectTree.java:182)
	at com.intellij.openapi.util.objectTree.ObjectTree.executeUnregistered(ObjectTree.java:194)
	at com.intellij.openapi.util.objectTree.ObjectTree.executeAll(ObjectTree.java:147)
	at com.intellij.openapi.util.Disposer.dispose(Disposer.java:129)
	at com.intellij.openapi.util.Disposer.dispose(Disposer.java:125)
	at com.intellij.openapi.roots.impl.RootModelImpl.dispose(RootModelImpl.java:656)
	at com.intellij.openapi.roots.impl.ModuleRootManagerImpl$1.dispose(ModuleRootManagerImpl.java:106)
	at com.intellij.openapi.roots.ModuleRootModificationUtil.updateModel(ModuleRootModificationUtil.java:148)
	at intellij.haskell.module.HaskellModuleBuilder$.removeModuleLibrary(HaskellModuleBuilder.scala:335)
	at intellij.haskell.module.HaskellModuleBuilder$.$anonfun$addPackagesAsDependenciesToModule$1(HaskellModuleBuilder.scala:295)
	at scala.collection.IndexedSeqOptimized.foreach(IndexedSeqOptimized.scala:32)
	at scala.collection.IndexedSeqOptimized.foreach$(IndexedSeqOptimized.scala:29)
	at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:194)
	at intellij.haskell.module.HaskellModuleBuilder$.addPackagesAsDependenciesToModule(HaskellModuleBuilder.scala:288)
	at intellij.haskell.module.HaskellModuleBuilder$.$anonfun$addLibrarySources$6(HaskellModuleBuilder.scala:262)
	at intellij.haskell.module.HaskellModuleBuilder$.$anonfun$addLibrarySources$6$adapted(HaskellModuleBuilder.scala:261)
	at scala.collection.mutable.ResizableArray.foreach(ResizableArray.scala:58)
	at scala.collection.mutable.ResizableArray.foreach$(ResizableArray.scala:51)
	at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
	at intellij.haskell.module.HaskellModuleBuilder$.$anonfun$addLibrarySources$1(HaskellModuleBuilder.scala:261)
	at intellij.haskell.module.HaskellModuleBuilder$.$anonfun$addLibrarySources$1$adapted(HaskellModuleBuilder.scala:242)
	at scala.Option.foreach(Option.scala:257)
	at intellij.haskell.module.HaskellModuleBuilder$.addLibrarySources(HaskellModuleBuilder.scala:242)
	at intellij.haskell.external.component.StackProjectManager$$anon$2.$anonfun$run$23(StackProjectManager.scala:206)
	at intellij.haskell.util.ScalaUtil$$anon$1.run(ScalaUtil.scala:36)
	at com.intellij.openapi.application.impl.ApplicationImpl$1.run(ApplicationImpl.java:314)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)

[rikvdkleij]

Should be fixed in next beta. It still takes some time but at least risk of deadlock should be gone.

[rikvdkleij]

Yeah, I know this issue. I thought it was fixed by waiting on smart mode before updating module settings. But apparently during updating the module settings also an index job can be started.

I have some change in mind. Hopefully that will solve it.