Migrated from http://lampsvn.epfl.ch/trac/scala/ticket/2680
Reporter spiros
How to reproduce the bug # Create a file with a class that has compile errors

1. Save the file to compile it
2. Delete the file

As a result we get the following errors in the Error Log view:

Error
Sun Nov 22 18:50:48 EET 2009
Resource '/bugs/src/bugs/Hello.scala' does not exist.

and

Warning
Sun Nov 22 18:50:48 EET 2009
Errors running builder 'Scala Builder' on project 'bugs'.

org.eclipse.core.internal.resources.ResourceException: Resource '/bugs/src/bugs/Hello.scala' does not exist.
	at org.eclipse.core.internal.resources.Resource.checkExists(Resource.java:319)
	at org.eclipse.core.internal.resources.Resource.checkAccessible(Resource.java:196)
	at org.eclipse.core.internal.resources.Resource.deleteMarkers(Resource.java:764)
	at scala.tools.eclipse.util.FileUtils$$anon$1.run(FileUtils.scala:37)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1800)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1782)
	at scala.tools.eclipse.util.FileUtils$.clearBuildErrors(FileUtils.scala:36)
	at scala.tools.eclipse.EclipseBuildManager$$anonfun$buildingFiles$1.apply(EclipseBuildManager.scala:140)
	at scala.tools.eclipse.EclipseBuildManager$$anonfun$buildingFiles$1.apply(EclipseBuildManager.scala:137)
	at scala.collection.mutable.HashSet.foreach(HashSet.scala:48)
	at scala.tools.eclipse.EclipseBuildManager.buildingFiles(EclipseBuildManager.scala:137)
	at scala.tools.nsc.interactive.RefinedBuildManager.update0$1(RefinedBuildManager.scala:94)
	at scala.tools.nsc.interactive.RefinedBuildManager.update(RefinedBuildManager.scala:138)
	at scala.tools.nsc.interactive.RefinedBuildManager.update(RefinedBuildManager.scala:80)
	at scala.tools.eclipse.EclipseBuildManager.build(EclipseBuildManager.scala:119)
	at scala.tools.eclipse.ScalaProject.build(ScalaProject.scala:366)
	at scala.tools.eclipse.ScalaBuilder.build(ScalaBuilder.scala:78)
	at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:627)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:170)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:201)
	at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:253)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:256)
	at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:309)
	at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:341)
	at org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:140)
	at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:238)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

Subsequent compilations (via save) produce the save error. If we do a clean+rebuild we do not get the error but any future compilations via save again produce the same error. The only way to stop having the error is to close the project and reopen it (but I believe that even then the Scala builder is in an inconsistent state).
Tested with Eclipse 3.5.1 and SDT r19761.