https://bugs.winehq.org/show_bug.cgi?id=21483
--- Comment #6 from Austin English austinenglish@gmail.com --- Still present in 1.7.11.
FWIW, dotnet20sdk is now in winetricks, so you can reproduce this by doing:
$ vi hello.cs $ winetricks -q dotnet20sdk $ wine "c:\windows\Microsoft.NET\Framework\v2.0.50727\csc.exe" /debug hello.cs $ wine "c:\Program Files\Microsoft.NET\SDK\v2.0\Bin\cordbg.exe" hello.exe