With HIDAPI option ... g -isystem /usr/local/include -fno-strict-aliasing -std=c99 -fdebug-prefix-map=/tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12=. -DLIBICONV_PLUG -isystem /usr/local/include -DUSING_GENERATED_CONFIG_H -Iinclude -I/tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/include -idirafter /tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/src/video/khronos -mmmx -msse -msse2 -Wall -fno-strict-aliasing -fvisibility=hidden -Wdeclaration-after-statement -Werror=declaration-after-statement -I/usr/local/include -I/usr/local/include -I/usr/local/include/libdrm -I/usr/local/include -DHAVE_USBHID_H -DUSBHID_NEW -I/tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/src/hidapi/hidapi -D_REENTRANT -D_THREAD_SAFE -MMD -MT build/SDL_hidapi.lo -c /tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/src/hidapi/SDL_hidapi.c -o build/SDL_hidapi.lo libtool: compile: cc -O2 -pipe -O3 -pipe -funroll-loops -DSTRIP_FBSDID -D_FORTIFY_SOURCE=2 -mretpoline -DLIBICONV_PLUG -fstack-protector-strong -isystem /usr/local/include -fno-strict-aliasing -std=c99 -fdebug-prefix-map=/tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12=. -DLIBICONV_PLUG -isystem /usr/local/include -DUSING_GENERATED_CONFIG_H -Iinclude -I/tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/include -idirafter /tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/src/video/khronos -mmmx -msse -msse2 -Wall -fno-strict-aliasing -fvisibility=hidden -Wdeclaration-after-statement -Werror=declaration-after-statement -I/usr/local/include -I/usr/local/include -I/usr/local/include/libdrm -I/usr/local/include -DHAVE_USBHID_H -DUSBHID_NEW -I/tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/src/hidapi/hidapi -D_REENTRANT -D_THREAD_SAFE -MMD -MT build/SDL_hidapi.lo -c /tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/src/hidapi/SDL_hidapi.c -fPIC -DPIC -o build/.libs/SDL_hidapi.o /tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/src/hidapi/SDL_hidapi.c:101:2: error: Need a hid.c for this platform! #error Need a hid.c for this platform! ^ /tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/src/hidapi/SDL_hidapi.c:305:5: error: type name requires a specifier or qualifier F(hid_write); ^ /tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/src/hidapi/SDL_hidapi.c:304:14: note: expanded from macro 'F' #define F(x) typeof(x) *x ^ /tmp/ports/usr/ports/devel/sdl20/work/SDL2-2.0.12/src/hidapi/SDL_hidapi.c:305:7: error: a parameter list without types is only allowed in a function definition F(hid_write); ^ ....
2.0.18 builds fine with HIDAPI