Support for ASP.NET (XSP)

Hi, I had trouble debugging an ASP.NET 4.5 web app earlier. Normally Xamarin or VS4Mac would suffice, but I need two debuggers going at once. The VSCode debugger was attaching, and I saw threads in the lower left, but it never paused at my breakpoints. I finally realized that I had disabled debug symbols and that was the reason why the breakpoints weren't being hit. Silly mistake, but I feel more docs are needed for this particular use case.

I figured out how to start my (Nancy) app like this:

$ MONO_OPTIONS="--debug --debugger-agent=transport=dt_socket,server=y,suspend=n,address=127.0.0.1:55555"  xsp4 --address 0.0.0.0 --port 8080 --verbose --root Content/

Strange behaviors I encountered (these might be more to do with mono and/or Nancy framework):

• Adding ,suspend=n to the debugger options seems like the only way I could make it hit breakpoints.

• Sometimes it seems to work better if the root is set to the full project folder path.

• In order for it to actually hit the breakpoints though, I need to hit a route on the app before I attach the debugger. This is the case on both mono 4.6.2 & 4.8.0.

Please let me know if you have any ideas about these issues, or if you need help with docs.

BTW, a month or two ago I forked this project and started a 'mono-xsp' debugger/launcher to try to eliminate the need for setting specific MONO_OPTIONS, but I couldn't figure out how to address/fix these problems. If anyone else sees the need for the launcher, I can forge ahead.

Start with the MONO_OPTIONS and xsp4 command shown in the issue, then review the existing debugger documentation for ASP.NET/XSP attachment and breakpoints. Done means documenting the setup, debug-symbol requirement, and the observed route-loading behavior, while clearly separating confirmed guidance from unresolved Mono or Nancy issues.