scenario:
- open the test/example.ent in the editor.
- go to entity URL
- press return after the location : String
- press CTRL-space to pop up the context assist in eclipse

• then the following NPE happens

eclipse.buildId=M20100211-1343
java.version=1.6.0_20
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=de_DE
Command-line arguments: -os win32 -ws win32 -arch x86

Error
Fri Jun 11 13:23:57 CEST 2010
Internal error evaluating strategy editor-complete

java.lang.NullPointerException
at org.spoofax.interpreter.stratego.Build.buildList(Build.java:247)
at org.spoofax.interpreter.stratego.Build.buildCons(Build.java:221)
at org.spoofax.interpreter.stratego.Build.buildList(Build.java:241)
at org.spoofax.interpreter.stratego.Build.buildCons(Build.java:221)
at org.spoofax.interpreter.stratego.Build.buildOp(Build.java:185)
at org.spoofax.interpreter.stratego.Build.buildTerm(Build.java:59)
at org.spoofax.interpreter.stratego.Build.buildAnno(Build.java:273)
at org.spoofax.interpreter.stratego.Build.buildTerm(Build.java:56)
at org.spoofax.interpreter.stratego.Build.eval(Build.java:42)
at org.spoofax.interpreter.stratego.Strategy.evaluate(Strategy.java:96)
at org.spoofax.interpreter.core.Interpreter.invoke(Interpreter.java:69)
at org.strategoxt.HybridInterpreter.invoke(HybridInterpreter.java:348)
at org.strategoxt.imp.runtime.services.StrategoObserver.invoke(StrategoObserver.java:551)
at org.strategoxt.imp.runtime.services.StrategoObserver.invokeSilent(StrategoObserver.java:586)
at org.strategoxt.imp.runtime.services.ContentProposer$1Runner.run(ContentProposer.java:221)
at org.strategoxt.imp.runtime.services.ContentProposer.invokeCompletionFunction(ContentProposer.java:236)
at org.strategoxt.imp.runtime.services.ContentProposer.getContentProposals(ContentProposer.java:132)
at org.strategoxt.imp.runtime.dynamicloading.DynamicContentProposer.getContentProposals(DynamicContentProposer.java:19)
at org.eclipse.imp.editor.internal.CompletionProcessor.computeCompletionProposals(CompletionProcessor.java:53)
at org.eclipse.jface.text.contentassist.ContentAssistant.computeCompletionProposals(ContentAssistant.java:1832)
at org.eclipse.jface.text.contentassist.CompletionProposalPopup.computeProposals(CompletionProposalPopup.java:556)
at org.eclipse.jface.text.contentassist.CompletionProposalPopup.access$16(CompletionProposalPopup.java:553)
at org.eclipse.jface.text.contentassist.CompletionProposalPopup$2.run(CompletionProposalPopup.java:488)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.text.contentassist.CompletionProposalPopup.showProposals(CompletionProposalPopup.java:482)
at org.eclipse.jface.text.contentassist.ContentAssistant.showPossibleCompletions(ContentAssistant.java:1660)
at org.eclipse.jface.text.source.SourceViewer.doOperation(SourceViewer.java:835)
at org.eclipse.jface.text.source.projection.ProjectionViewer.doOperation(ProjectionViewer.java:1533)
at org.eclipse.imp.editor.StructuredSourceViewer.doOperation(StructuredSourceViewer.java:140)
at org.eclipse.ui.texteditor.ContentAssistAction$1.run(ContentAssistAction.java:82)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.texteditor.ContentAssistAction.run(ContentAssistAction.java:80)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:498)
at org.eclipse.ui.commands.ActionHandler.execute(ActionHandler.java:185)
at org.eclipse.ui.internal.handlers.LegacyHandlerWrapper.execute(LegacyHandlerWrapper.java:109)
at org.eclipse.core.commands.Command.executeWithChecks(Command.java:476)
at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
at org.eclipse.ui.internal.handlers.HandlerService.executeCommand(HandlerService.java:169)
at org.eclipse.ui.internal.keys.WorkbenchKeyboard.executeCommand(WorkbenchKeyboard.java:470)
at org.eclipse.ui.internal.keys.WorkbenchKeyboard.press(WorkbenchKeyboard.java:824)
at org.eclipse.ui.internal.keys.WorkbenchKeyboard.processKeyEvent(WorkbenchKeyboard.java:880)
at org.eclipse.ui.internal.keys.WorkbenchKeyboard.filterKeySequenceBindings(WorkbenchKeyboard.java:569)
at org.eclipse.ui.internal.keys.WorkbenchKeyboard.access$3(WorkbenchKeyboard.java:510)
at org.eclipse.ui.internal.keys.WorkbenchKeyboard$KeyDownFilter.handleEvent(WorkbenchKeyboard.java:125)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.filterEvent(Display.java:1208)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1002)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1027)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1012)
at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1040)
at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1036)
at org.eclipse.swt.widgets.Widget.wmChar(Widget.java:1368)
at org.eclipse.swt.widgets.Control.WM_CHAR(Control.java:4053)
at org.eclipse.swt.widgets.Canvas.WM_CHAR(Canvas.java:346)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:3946)
at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:342)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4619)
at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:2411)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3501)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2405)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2369)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2221)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:500)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:493)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:113)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:194)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:368)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:559)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514)
at org.eclipse.equinox.launcher.Main.run(Main.java:1311)

Submitted by Bernhard Merkle on 11 June 2010 at 14:00

Thanks for reporting :) This bug has been fixed in 0.5.1, which is currently still being tested internally. Should be released next week.