.NET 9.0 Debugging Issue - F10 Step Over executes multiple steps

I recently ran into a debugging issue with my latest VisualStudio 2022 update and Resharper C# installation. It's important to note that I didn't start using this setup until I'd upgraded my projects to .NET 9.0.

I was able to hit breakpoints but found that while stepping over statements (F10), the debugger would sometimes run to the next breakpoint, execute a random number of steps forward to a different line in the call stack, or run to completion. The issue was intermittent too. Ugh. I also use a number of VisualStudio extensions so that didn't make it any easier to find the cause. I ended up trying the following to no avail:

1. disabling Resharper's Async Typing and Debugger Integration. I'd seen some race conditions with the Async Typing and since the debugging issue was intermittent I figured I'd try disabling Async Typing even though it didn't have any apparent connection to the debugger. 
2. disabling all extensions 
3. uninstalling all extensions 
4. repairing the VisualStudio installation

Once I was down to a bare bones VisualStudio installation I figured it was VisualStudio itself. By this time I didn't want to continue debugging by deduction any longer so I didn't want to go down the road of rolling back to previous VisualStudio versions. I went on to the Feedback Forum for VisualStudio to look for an existing bug and open one if I couldn't find one there. I came upon this issue in the Developer Forum: Debugger randomly stepping over user code. It never occurred to me that I was now using .NET 9 and the problem could've been related. 🤯

I ultimately found the following issues opened for the .NET 9.0 runtime which all had the same root cause:

• Debugging Issue VS 2022 .net 9 #110841
• Step becomes a "go" in .NET 9 #109785
• foreach will jump to other code in dotnet9 #109812
• Step Over sometimes executes a lot more than one statement #109885
• And the fix merged here: #110533

The fix was pretty small and there were only two files changed:

The Controller in the CoreClr's Debugger Execution Engine:

And the Thread Suspension class:

Ironically, as I was writing this post I got an email about .NET 9.0.1 being released. I couldn't find any of the issues or the PR for the fix included in the Release Notes. I went back to the Fix a step that becomes a go #110533 PR notes and saw that the Milestone for the fix is 9.0.2 (release date TBD). I was disappointed to find that the fix was not included in the .NET 9.0.1 Release but happy that it is coming in the next release of 9.0.2.