Bug in SDL_CreateThread (unit sdl.pas)
In the following unit, line 3901, SDL_CreateThread(... is wrong. .../fpcsrc/packages/sdl/src/sdl.pas I fixed it like this and it works:
Old:
// function SDL_CreateThread(fn: PInt; data: Pointer): PSDL_Thread;
New:
function SDL_CreateThread(fn: Pointer; data: Pointer): PSDL_Thread;
Tested with a 64-bit Linux
Source:
https://gitlab.com/freepascal.org/fpc/source/-/blob/main/packages/sdl/src/sdl.pas