Visual Studio 2019 crashes with mixed debugging (.Net Core)

[fobrs]

The latest version of Visual Studio 2019 (16.5.2) crashes when in a mixed debugging (.Net Core) session.

As soon as you want to look at a managed variable the crash occurs. So if you want to look at the value of _managedState, Visual Studio 2019 crashes.

Event Viewer shows:

Faulting module name: unknown, version: 0.0.0.0, time stamp: 0x00000000
Exception code: 0xc0000005
Fault offset: 0x01548ca0
Faulting process id: 0x2914
Faulting application start time: 0x01d607a4b457b6d1
Faulting application path: E:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\Common7\IDE\devenv.exe
Faulting module path: unknown
Report Id: a0ae67a1-4bdf-4467-9c83-6c9549ac87a2
Faulting package full name: 
Faulting package-relative application ID:

And:

Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.NullReferenceException
   at MCppEE.QueryAssemblyCompiler.GetIlasmNameInternal(MCppEE.Type, Boolean, Boolean)
   at MCppEE.QueryAssemblyCompiler.GetIlasmName(MCppEE.Type, Boolean)
   at MCppEE.QueryAssemblyCompiler.GetIlasmNameInternal(MCppEE.Type, Boolean, Boolean)
   at MCppEE.FunctionBuilder.GetFunctionDefinition()
   at MCppEE.CompilerEntryPoint.GetClrLocalVariableQuery(Microsoft.VisualStudio.Debugger.Evaluation.DkmInspectionContext, Microsoft.VisualStudio.Debugger.Clr.DkmClrInstructionAddress, Boolean)
   at Microsoft.VisualStudio.Debugger.EntryPoint.IDkmClrExpressionCompiler_GetClrLocalVariableQuery(IntPtr, IntPtr, IntPtr, Byte, IntPtr ByRef)

Apparently mixed .Net Core debugging is using .Net Framework!

[mjrousos]

Thanks, @fobrs, for reporting the issue. I see it, as well. @tgani-msft, @wli3, @olgaark, any ideas whether this is a known issue or who we could loop in to dig deeper?

I can reproduce the issue. Inspecting a managed variable in a mixed-mode assembly while debugging type set to "Mixed (.NET Core)" crashes, as described here. I tested with 16.6 preview 1.

[fobrs]

https://developercommunity.visualstudio.com/content/problem/902753/ccli-debug-in-net-core-31-crash.html

[tgani]

@mjrousos, I think the best way is to file a bug and have the debugger team take a look (@caslan is the lead, I believe).

[eightcloud83]

Crashed bug has been fixed @ 16.6 preivew 3,
but I still cannot "Watch" c++'s variable in .NetCore like in .NetFramework.

I'v reported another problem,
https://developercommunity.visualstudio.com/content/problem/996978/ccli-debug-watch-problem-in-net-core-31.html

If you have same broblem, you can vote the problem.

c++/cli in .net framework: no problem

c++/cli in .net core 3.1: can not watch the variable

[eightcloud83]

Yes! Fixed in16.7 preview 5.

donot forget to enable native debugging