When attempting to build the SDL version, did you first run:
$./configure --enable-sdl ?
That should create the missing main_bas.h file
Of course, I did. If I didn't there would be no error message, because the console version would be compiled again. BTW main_bas.h file is not missing - I can see it in SmallBASIC-master/src/platform/sdl/ directory...
Does your main_bas.h look something like this:
unsigned char main_bas[] = {
0x63, 0x6f, 0x6e, 0x73, 0x74, 0x20, 0x61, 0x70, 0x70, 0x20, 0x3d, 0x20,
...
0x0a, 0x6d, 0x61, 0x69, 0x6e, 0x0a
};
unsigned int main_bas_len = 17358;