Ok, it seems to be finding SDL1's headers, e.g. <SDL.h> instead of SDL2's headers, e.g. <SDL2/SDL.h>. The line

  find ./ -type f -exec sed -i 's/#include "SDL/#include "SDL2\/SDL/' {} \; 

made it work on my box (but would of course break it on any box where SDL2 is the default). Isn't this the sort of thing autotools/cmake/whatever are supposed to take care of?

Anyway, since it apparently can't compile against SDL1's headers, you might want to update INSTALL.txt to reflect that.

A very homebrew Linux system. Toolchain, though, is: gcc 4.8.2, glibc 2.19, binutils 2.24. And I had first tried with SDL2-2.0.4; I upgraded after it didn't work with that one.

I'm trying to compile v0.54 and get a bunch of error messages involving "SDL_Keycode" --- first is /sources/ivan-054/FeLib/Include/whandler.h:78:49: error: expected ',' or '...' before '(' token
static void SetFunctionKeyHandler(bool (*What)(SDL_Keycode)){ FunctionKeyHandler = What; }
SDL2 version is 2.0.9. What am I missing?