[xUnit.net 00:00:01.02]     FSharp.Compiler.UnitTests.SpanTests.Script_ReadOnlySpanForInDo [FAIL]
[xUnit.net 00:00:01.02]       System.Exception : Error creating evaluation session: System.AggregateException: One or more errors occurred. (Value cannot be null.)
[xUnit.net 00:00:01.02]        ---> System.ArgumentNullException: Value cannot be null.
[xUnit.net 00:00:01.02]          at System.Threading.Monitor.Enter(Object obj)
[xUnit.net 00:00:01.02]          at FSharp.Compiler.AbstractIL.IL.ILPreTypeDefImpl.FSharp.Compiler.AbstractIL.IL.ILPreTypeDef.GetTypeDef() in E:\repos\fsharp\src\Compiler\AbstractIL\il.fs:line 2927
[xUnit.net 00:00:01.02]          at [email protected](Tuple`2 tupledArg) in E:\repos\fsharp\src\Compiler\Checking\import.fs:line 731
[xUnit.net 00:00:01.02]          at FSharp.Compiler.Import.multisetDiscriminateAndMap[Key,Value,a](FSharpFunc`2 nodef, FSharpFunc`2 tipf, FSharpList`1 items) in E:\repos\fsharp\src\Compiler\Checking\import.fs:line 689
[xUnit.net 00:00:01.02]          at FSharp.Compiler.Import.ImportILTypeDefList(FSharpFunc`2 amap, Range m, CompilationPath cpath, FSharpList`1 enc, FSharpList`1 items) in E:\repos\fsharp\src\Compiler\Checking\import.fs:line 724
[xUnit.net 00:00:01.02]          at [email protected](Unit _arg2) in E:\repos\fsharp\src\Compiler\Checking\import.fs:line 727
[xUnit.net 00:00:01.02]          at Internal.Utilities.Library.InterruptibleLazy`1.get_Value() in E:\repos\fsharp\src\Compiler\Utilities\illib.fs:line 33
[xUnit.net 00:00:01.02]          at Internal.Utilities.Library.Extras.MaybeLazy`1.Force() in E:\repos\fsharp\src\Compiler\Utilities\lib.fs:line 396
[xUnit.net 00:00:01.02]          at FSharp.Compiler.CompilerImports.TcImports.ccuHasType(CcuThunk ccu, FSharpList`1 nsname, String tname, Boolean publicOnly) in E:\repos\fsharp\src\Compiler\Driver\CompilerImports.fs:line 1296
[xUnit.net 00:00:01.02]          at FSharp.Compiler.CompilerImports.TcImports.tryFindSysTypeCcu@2596-1.Invoke(CcuThunk ccu) in E:\repos\fsharp\src\Compiler\Driver\CompilerImports.fs:line 2596
[xUnit.net 00:00:01.02]          at Microsoft.FSharp.Collections.ArrayModule.loop@1144-40[T](FSharpFunc`2 predicate, T[] array, Int32 i) in E:\repos\fsharp\src\FSharp.Core\array.fs:line 1147
[xUnit.net 00:00:01.02]          at Microsoft.FSharp.Collections.ArrayModule.TryFind[T](FSharpFunc`2 predicate, T[] array) in E:\repos\fsharp\src\FSharp.Core\array.fs:line 1152
[xUnit.net 00:00:01.02]          at FSharp.Compiler.TcGlobals.TcGlobals.tryFindSysTypeCcu(FSharpList`1 path, String nm) in E:\repos\fsharp\src\Compiler\TypedTree\TcGlobals.fs:line 216
[xUnit.net 00:00:01.02]          at FSharp.Compiler.TcGlobals.TcGlobals.tryFindSysAttrib(String nm) in E:\repos\fsharp\src\Compiler\TypedTree\TcGlobals.fs:line 320
[xUnit.net 00:00:01.02]          at FSharp.Compiler.TcGlobals.TcGlobals..ctor(Boolean compilingFSharpCore, ILGlobals ilg, CcuThunk fslibCcu, String directoryToResolveRelativePaths, Boolean mlCompatibility, Boolean isInteractive, Boolean checkNullness, Boolean useReflectionFreeCodeGen, FSharpFunc`2 tryFindSysTypeCcuHelper, Boolean emitDebugInfoInQuotations, Boolean noDebugAttributes, PathMap pathMap, LanguageVersion langVersion, Boolean realsig) in E:\repos\fsharp\src\Compiler\TypedTree\TcGlobals.fs:line 1079
[xUnit.net 00:00:01.02]          at FSharp.Compiler.CompilerImports.TcImports.BuildFrameworkTcImports@2589-10.Invoke(FSharpList`1 _arg10) in E:\repos\fsharp\src\Compiler\Driver\CompilerImports.fs:line 2602
[xUnit.net 00:00:01.02]          at Microsoft.FSharp.Control.AsyncPrimitives.CallThenInvokeNoHijackCheck[a,b](AsyncActivation`1 ctxt, b result1, FSharpFunc`2 userCode) in E:\repos\fsharp\src\FSharp.Core\async.fs:line 528
[xUnit.net 00:00:01.02]          at Microsoft.FSharp.Control.Trampoline.Execute(FSharpFunc`2 firstAction) in E:\repos\fsharp\src\FSharp.Core\async.fs:line 112
[xUnit.net 00:00:01.02]          --- End of inner exception stack trace ---
[xUnit.net 00:00:01.02]          at Internal.Utilities.Library.PervasiveAutoOpens.Async.RunImmediate.Static[T](FSharpAsync`1 computation, FSharpOption`1 cancellationToken) in E:\repos\fsharp\src\Compiler\Utilities\illib.fs:line 151
[xUnit.net 00:00:01.02]          at FSharp.Compiler.Interactive.Shell.FsiEvaluationSession..ctor(FsiEvaluationSessionHostConfig fsi, String[] argv, TextReader inReader, TextWriter outWriter, TextWriter errorWriter, Boolean fsiCollectible, FSharpOption`1 legacyReferenceResolver) in E:\repos\fsharp\src\Compiler\Interactive\fsi.fs:line 4673
[xUnit.net 00:00:01.02]       Stack Trace:
[xUnit.net 00:00:01.02]            at Microsoft.FSharp.Core.PrintfModule.PrintFormatToStringThenFail@1448.Invoke(String message)
[xUnit.net 00:00:01.02]         E:\repos\fsharp\src\Compiler\Interactive\fsi.fs(4676,0): at FSharp.Compiler.Interactive.Shell.FsiEvaluationSession..ctor(FsiEvaluationSessionHostConfig fsi, String[] argv, TextReader inReader, TextWriter outWriter, TextWriter errorWriter, Boolean fsiCollectible, FSharpOption`1 legacyReferenceResolver)
[xUnit.net 00:00:01.02]         E:\repos\fsharp\src\Compiler\Interactive\fsi.fs(5007,0): at FSharp.Compiler.Interactive.Shell.FsiEvaluationSession.Create(FsiEvaluationSessionHostConfig fsiConfig, String[] argv, TextReader inReader, TextWriter outWriter, TextWriter errorWriter, FSharpOption`1 collectible, FSharpOption`1 legacyReferenceResolver)
[xUnit.net 00:00:01.02]         E:\repos\fsharp\tests\FSharp.Test.Utilities\CompilerAssert.fs(1004,0): at FSharp.Test.CompilerAssert.RunScriptWithOptionsAndReturnResult(String[] options, String source)
[xUnit.net 00:00:01.02]         E:\repos\fsharp\tests\FSharp.Test.Utilities\CompilerAssert.fs(1019,0): at FSharp.Test.CompilerAssert.RunScriptWithOptions(String[] options, String source, FSharpList`1 expectedErrorMessages)
[xUnit.net 00:00:01.02]         E:\repos\fsharp\tests\FSharp.Test.Utilities\CompilerAssert.fs(1029,0): at FSharp.Test.CompilerAssert.RunScript(String source, FSharpList`1 expectedErrorMessages)
[xUnit.net 00:00:01.02]         E:\repos\fsharp\tests\fsharp\Compiler\Language\SpanTests.fs(91,0): at FSharp.Compiler.UnitTests.SpanTests.Script_ReadOnlySpanForInDo()
[xUnit.net 00:00:01.02]            at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
[xUnit.net 00:00:01.02]            at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)
[xUnit.net 00:00:05.32]       failing on main