Crash with modules with only extension methods

[edhzsz]

The following module

[<System.Runtime.CompilerServices.Extension>]
module ExtensionMethods =
   [<System.Runtime.CompilerServices.Extension>]
   let Exists(opt : Module option) = opt.IsSome

Crashes when it does not have [omit] with the following stack trace

Microsoft.FSharp.Compiler.ErrorLogger+StopProcessing: Exception of type 'Microsoft.FSharp.Compiler.ErrorLogger+StopProcessing' was thrown.
  at Microsoft.FSharp.Compiler.Interactive.Shell.ErrorLoggerThatStopsOnFirstError.ErrorSinkHelper[a](PhasedError err) in C:\GitHub\fsharp\FSharp.Compiler.Service\src\fsharp\fsi\fsi.fs:line 482
  at Microsoft.FSharp.Compiler.Interactive.Shell.ErrorLoggerThatStopsOnFirstError.ErrorSinkImpl(PhasedError err) in C:\GitHub\fsharp\FSharp.Compiler.Service\src\fsharp\fsi\fsi.fs:line 497
  at Microsoft.FSharp.Compiler.ErrorLogger.ErrorLoggerExtensions.ErrorLogger.Error[b](ErrorLogger x, Exception exn) in C:\GitHub\fsharp\FSharp.Compiler.Service\src\fsharp\ErrorLogger.fs:line 321
  at Microsoft.FSharp.Compiler.Tast.EntityRef.get_Deref() in C:\GitHub\fsharp\FSharp.Compiler.Service\src\fsharp\tast.fs:line 2585
  at Microsoft.FSharp.Compiler.SourceCodeServices.FSharpEntity.get_CompiledName() in C:\GitHub\fsharp\FSharp.Compiler.Service\src\fsharp\vs\Symbols.fs:line 211
  at [email protected](FSharpAttribute a)
  at Microsoft.FSharp.Collections.SeqModule.Exists[T](FSharpFunc`2 predicate, IEnumerable`1 source)
  at FSharp.MetadataFormat.ValueReader.buildUsage@342(FSharpMemberOrFunctionOrValue v, FSharpOption`1 args)
  at [email protected](Int32 length)
  at RazorEngine.Compilation.ImpromptuInterface.Optimization.InvokeHelper.InvokeMemberTargetType[TTarget,TReturn](CallSite& callsite, Type binderType, Int32 knownType, LazyBinder binder, String_OR_InvokeMemberName name, Boolean staticContext, Type context, String[] argNames, TTarget target, Object[] args)
  at RazorEngine.Compilation.ImpromptuInterface.Optimization.InvokeHelper.InvokeMemberCallSite(Object target, String_OR_InvokeMemberName name, Object[] args, String[] tArgNames, Type tContext, Boolean tStaticContext, CallSite& callSite)
  at RazorEngine.Compilation.ImpromptuInterface.Impromptu.InvokeMember(Object target, String_OR_InvokeMemberName name, Object[] args)
  at RazorEngine.Compilation.ImpromptuInterface.Dynamic.Invocation.Invoke(Object target, Object[] args)
  at RazorEngine.Compilation.ImpromptuInterface.Dynamic.Invocation.InvokeWithStoredArgs(Object target)
  at RazorEngine.Compilation.RazorDynamicObject.MarshalWrapper.GetResult(Invocation invocation)
  at RazorEngine.Compilation.RazorDynamicObject.RemoteInvoke(Invocation invocation, Object& result)
  at RazorEngine.Compilation.RazorDynamicObject.TryInvokeMember(InvokeMemberBinder binder, Object[] args, Object& result)
  at CallSite.Target(Closure , CallSite , Object , Int32 )
  at CompiledRazorTemplates.Dynamic.RazorEngine_9128ddeeeb894d75a45feeca04f65f76.Execute()
  at RazorEngine.Templating.TemplateBase.RazorEngine.Templating.ITemplate.Run(ExecuteContext context, TextWriter reader)
  at RazorEngine.Templating.TemplateBase.<>c__DisplayClass3.<Include>b__2(TextWriter tw)
  at RazorEngine.Templating.TemplateWriter.WriteTo(TextWriter writer)
  at RazorEngine.Templating.TemplateBase.Write(TemplateWriter helper)
  at CompiledRazorTemplates.Dynamic.RazorEngine_6b81022106eb49548f3e4b4115f740e7.Execute()
  at RazorEngine.Templating.TemplateBase.RazorEngine.Templating.ITemplate.Run(ExecuteContext context, TextWriter reader)
  at RazorEngine.Templating.RazorEngineCore.RunTemplate(ICompiledTemplate template, TextWriter writer, Object model, DynamicViewBag viewBag)
  at RazorEngine.Templating.RazorEngineService.RunCompile(ITemplateKey key, TextWriter writer, Type modelType, Object model, DynamicViewBag viewBag)
  at RazorEngine.Templating.DynamicWrapperService.RunCompile(ITemplateKey key, TextWriter writer, Type modelType, Object model, DynamicViewBag viewBag)
  at RazorEngine.Templating.RazorEngineServiceExtensions.<>c__DisplayClass1.<RunCompile>b__0(TextWriter writer)
  at RazorEngine.Templating.RazorEngineServiceExtensions.WithWriter(Action`1 withWriter)
  at RazorEngine.Templating.RazorEngineServiceExtensions.RunCompile(IRazorEngineService service, ITemplateKey key, Type modelType, Object model, DynamicViewBag viewBag)
  at <StartupCode$FSharp-MetadataFormat>[email protected](Unit _arg1)
  at FSharp.MetadataFormat.RazorRender.handleCompile[a](String source, FSharpFunc`2 f)
  at FSharp.MetadataFormat.RazorRender.ProcessFileModel[b](Type modelType, Object model, FSharpOption`1 properties)
  at FSharp.MetadataFormat.RazorRender`1.ProcessFile[a](model model, FSharpOption`1 properties)
  at FSharp.MetadataFormat.MetadataFormat.Generate(FSharpList`1 dllFiles, String outDir, FSharpList`1 layoutRoots, FSharpOption`1 parameters, FSharpOption`1 namespaceTemplate, FSharpOption`1 moduleTemplate, FSharpOption`1 typeTemplate, FSharpOption`1 xmlFile, FSharpOption`1 sourceRepo, FSharpOption`1 sourceFolder, FSharpOption`1 publicOnly, FSharpOption`1 libDirs, FSharpOption`1 otherFlags, FSharpOption`1 markDownComments, FSharpOption`1 urlRangeHighlight, FSharpOption`1 assemblyReferences)
  at <StartupCode$FSI_0004>.$FSI_0004.main@() in C:\Users\hernaned\Documents\GitHub\FSharp.Formatting\docs\tools\generate.fsx:line 138

[edhzsz]

Duplicate of #201