It's been a year and my pcem forum account hasn't been activated, so I can't ask for help there.

When I try to compile myself, I get the following errors; perhaps someone else has gotten past this?

/usr/bin/ld: pcem-wx-sdl2-joystick.o: in function `joystick_init':
wx-sdl2-joystick.c:(.text+0x124): undefined reference to `SDL_InitSubSystem'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x128): undefined reference to `SDL_NumJoysticks'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x18c): undefined reference to `SDL_JoystickOpen'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x1ac): undefined reference to `SDL_JoystickName'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x1c4): undefined reference to `SDL_JoystickNumAxes'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x1d8): undefined reference to `SDL_JoystickNumButtons'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x1ec): undefined reference to `SDL_JoystickNumHats'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x200): undefined reference to `SDL_JoystickNameForIndex'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x218): undefined reference to `SDL_JoystickNumAxes'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x224): undefined reference to `SDL_JoystickNumButtons'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x230): undefined reference to `SDL_JoystickNumHats'
/usr/bin/ld: pcem-wx-sdl2-joystick.o: in function `joystick_close':
wx-sdl2-joystick.c:(.text+0x374): undefined reference to `SDL_JoystickClose'
/usr/bin/ld: pcem-wx-sdl2-joystick.o: in function `joystick_poll':
wx-sdl2-joystick.c:(.text+0x3b8): undefined reference to `SDL_JoystickUpdate'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x3dc): undefined reference to `SDL_JoystickGetAxis'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x3f4): undefined reference to `SDL_JoystickGetAxis'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x404): undefined reference to `SDL_JoystickGetAxis'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x414): undefined reference to `SDL_JoystickGetAxis'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x424): undefined reference to `SDL_JoystickGetAxis'
/usr/bin/ld: pcem-wx-sdl2-joystick.o:wx-sdl2-joystick.c:(.text+0x434): more undefined references to `SDL_JoystickGetAxis' follow
/usr/bin/ld: pcem-wx-sdl2-joystick.o: in function `joystick_poll':
wx-sdl2-joystick.c:(.text+0x444): undefined reference to `SDL_JoystickGetButton'
/usr/bin/ld: wx-sdl2-joystick.c:(.text+0x468): undefined reference to `SDL_JoystickGetHat'
/usr/bin/ld: pcem-wx-sdl2-mouse.o: in function `mouse_poll_host':
wx-sdl2-mouse.c:(.text+0x70): undefined reference to `SDL_GetRelativeMouseState'
/usr/bin/ld: pcem-wx-sdl2-video.o: in function `sdl_blit_memtoscreen':
wx-sdl2-video.c:(.text+0x34): undefined reference to `SDL_LockMutex'
/usr/bin/ld: wx-sdl2-video.c:(.text+0xfc): undefined reference to `SDL_UnlockMutex'
/usr/bin/ld: pcem-wx-sdl2-video.o: in function `sdl_is_fullscreen':
wx-sdl2-video.c:(.text+0x750): undefined reference to `SDL_GetWindowFlags'
/usr/bin/ld: pcem-wx-sdl2-video.o: in function `sdl_video_init':
wx-sdl2-video.c:(.text+0x774): undefined reference to `SDL_CreateMutex'
/usr/bin/ld: pcem-wx-sdl2-video.o: in function `sdl_video_close':
wx-sdl2-video.c:(.text+0x920): undefined reference to `SDL_DestroyMutex'
/usr/bin/ld: pcem-wx-sdl2-video.o: in function `sdl_renderer_update':
wx-sdl2-video.c:(.text+0xa5c): undefined reference to `SDL_LockMutex'
/usr/bin/ld: wx-sdl2-video.c:(.text+0xa70): undefined reference to `SDL_UnlockMutex'
/usr/bin/ld: wx-sdl2-video.c:(.text+0xb00): undefined reference to `SDL_UnlockMutex'
/usr/bin/ld: pcem-wx-sdl2-video.o: in function `sdl_renderer_present':
wx-sdl2-video.c:(.text+0xba0): undefined reference to `SDL_GetWindowSize'
/usr/bin/ld: wx-sdl2-video.c:(.text+0xc14): undefined reference to `SDL_GetTicks'
/usr/bin/ld: pcem-wx-sdl2-video.o: in function `color_flash':
wx-sdl2-video.c:(.text+0xca8): undefined reference to `SDL_GetTicks'
/usr/bin/ld: pcem-wx-sdl2.o: in function `mainthread':
wx-sdl2.c:(.text+0x70): undefined reference to `SDL_SetThreadPriority'
/usr/bin/ld: wx-sdl2.c:(.text+0x78): undefined reference to `SDL_GetTicks'
/usr/bin/ld: wx-sdl2.c:(.text+0x98): undefined reference to `SDL_Delay'
/usr/bin/ld: wx-sdl2.c:(.text+0xac): undefined reference to `SDL_GetTicks'
/usr/bin/ld: wx-sdl2.c:(.text+0xdc): undefined reference to `SDL_GetPerformanceCounter'
/usr/bin/ld: wx-sdl2.c:(.text+0x118): undefined reference to `SDL_GetPerformanceCounter'
/usr/bin/ld: wx-sdl2.c:(.text+0x150): undefined reference to `SDL_LockMutex'