dotnet tools hanging when using SDK with Mono built runtime

[mthalman]

The dotnet format smoke test for source build ends up hanging indefinitely on the CentOSStream8_Mono_Offline_MsftSdk build leg of the VMR. This build leg uses a Mono built runtime.

I'm unable to get a .NET dump of the hung process, seemingly due to the incompatibility between the latest dotnet-dump tool (8.0) and the version of the .NET CLI process that is hung (9.0) (it gets the following error: Write dump failed - HRESULT: 0x80131515.). Instead, I was able to collect a Linux dump with gcore: out.zip

[mthalman]

Transferred this to the sdk repo to have someone take a look. I suspect this is not specific to format and could be a more general sdk issue because of a potentially related issue at dotnet/source-build#3792. If someone knows how to get a compatible .NET 9 dotnet-dump tool, I can try to get a dump using that.

[mthalman]

As I suspected, this isn't specific to dotnet-format. A hang is also occurring for dotnet-watch. So it's something more general around the dotnet tools or SDK itself.

[mthalman]

If someone knows how to get a compatible .NET 9 dotnet-dump tool, I can try to get a dump using that.

Also, apparently mono isn't supported by dotnet-dump.

[Forgind]

I tried to open your dump in VS, and it wouldn't let me debug with managed and told me there's no heap. I'm not sure if there's some other way to access its information?

[mthalman]

@janvorli - You're good at this stuff. What's the best way to debug what I've collected? Or how should I go about collecting a dump differently to make this better?