I was in the process of updating both PainlessSVN Professional and Console to version 1.2.1, when I found a bug in Visual Studio 2010 debugger. The solutions for both projects were in VS2008. My OS recently died, so I had to re-install it from scratch. I only installed VS2010, because I wanted to move away from VS2008.

My first hint that something was wrong was when I needed to modify the About dll to include the new version numbers and years in the copyright. This project is a C++ resource dll. This simple project would not compile on the VS2010 compiler when I converted it. I ended up firing one of my VMWare images that has VS2008 to get this done.

The next thing that happened was that none of the breakpoints I set worked, while trying to track down an unhandled exception. I went to Google and found that this is a known bug. The report is over here:

Debugging an MMC snapin does not attach correctly to mmc.exe

The suggested work around is here:

Can’t hit breakpoints in a plug-in or can’t debug .NET 2.0/3.0/3.5 from a mixed mode .exe project with Visual Studio 2010?

Unfortunately, that didn't work for me. What did work was to change the mmc.exe instance from the C:\Windows\SysWow64 to the one in C:\Windows\System32, then attach the debugger manually. The debugger will not attach to instances of the mmc.exe program in the SysWow64 directory. I am running VS2010 on Windows 7 Ultimate x64, and that's why I was using the 64 bit version of mmc.exe.

Anyways, hope this helps somebody else.