I've attached some pics with errors from MAME and KEGA. I've used SDL Framework 2.0.8 and no hope here still...
UPDATED!
Just finished to compile MAME here and now is all ok! So the last official build on http://sdlmame.lngn.net/ isnt working well on High Sierra I guess.
But KEGA or SNES emulators arent working I presume the need to be compiled in a MAC with the last Command Line Tools 10.13 for XCode to work but thinking on KEGA side I doubt if Steve Snake will do that