Anonymous Record error in fsi

[kevmal]

FSI has issues if on first use of an anonymous record an exception is thrown.

Repro steps

let a = {|A = 1|}
do failwith ""

Run the above twice in FSI. On first run an exception is thrown as exprected, on second run there's an error

C:\Users\User\AppData\Local\Temp\unknown(1,1): error FS3216: type '<>f__AnonymousType1324739542`1'' not found in assembly '<emitted>'. A possible cause may be a version incompatibility. You may need to explicitly reference the correct version of this assembly to allow all referenced components to use the correct version.

Expected behavior

Exception thrown both times.

Actual behavior

Error FS3216.

Known workarounds

Reset FSI.

Related information

Tested on VS2019 preview 4.4

[cartermp]

@dsyme FYI

[cartermp]

Confirmed as not resolved yet for VS 16.2.

[Happypig375]

Confirmed as not resolved yet for VS 16.3.2

[kevmal]

More specifically IlxAssemblyGenerator is maintaining a AnonTypeGenerationTable. State becomes inconsistent when a new type is added to the anonymous type table and an error is hit in user code here:

fsharp/src/fsharp/fsi/fsi.fs

Lines 1154 to 1166 in ec5bad3

	timeReporter.TimeOpIf istate.timing (fun () ->
	execs |> List.iter (fun exec ->
	match exec() with
	| Some err ->
	match errorLogger with
	| :? ErrorLoggerThatStopsOnFirstError as errorLogger ->
	fprintfn fsiConsoleOutput.Error "%s" (err.ToString())
	errorLogger.SetError()
	errorLogger.AbortOnError(fsiConsoleOutput)
	| _ ->
	raise (StopProcessingExn (Some err))
	| None -> ())) ;