https://bugs.winehq.org/show_bug.cgi?id=56932
--- Comment #3 from Maarten madebr@gmail.com --- Indeed, filling in the "PMINIDUMP_EXCEPTION_INFORMATION ExceptionParam" argument of MiniDumpWriteDump with the current Exception and Context record makes the null pointer dereference go away.
sdlprocdump has already successfully created minidumps on Windows, but I indeed noticed the exception record displayed as unknown in Visual Studio.