App randomly crashes on Windows with latest MinGW/MSYS

I build my app ( for Win32 with MinGW/MSYS. Uses SDL2, SDL2_image, SDL2_mixer.
Since this revision (, I tried upgrading MinGW/MSYS, which went bad due to existing-file conflicts, and so I did a full reinstall. Then I started to get random crashes with uninformative call stacks like:

#0 0x6c7b52e7 in SDL_LogCritical ()
from C:\MinGW\msys\1.0\home\Kevin\witchfire\SDL2.dll
#1 0x00002000 in ?? ()
#2 0x00000080 in ?? ()
#3 0x00000000 in ?? ()

Some of them are longer and have random SDL2_mixer functions in there. But I’ve yet to notice any pattern to how long the app lasts or where exactly in what executable it happens.

Oh, I tried going back to the revision before that one and still had similar crashes. Haven’t got any on Linux yet.

Any ideas or advice on this are appreciated.