I am on 2.3 retropie and trying to compile MAME after editing the minimal.cp to allow 6 axis controllers. When I do sudo make I get this.
rpi/drivers/magix.o obj_mame_rpi/drivers/royalmah.o obj_mame_rpi/drivers/neogeo.o -o mame
/usr/bin/ld: obj_mame_rpi/rpi/minimal.o: undefined reference to symbol 'clock_gettime@@GLIBC_2.4'
//lib/arm-linux-gnueabihf/librt.so.1: error adding symbols: DSO missing from command line
collect2: ld returned 1 exit status
Makefile:67: recipe for target 'mame' failed
Also when I try to compile pisNES getting around the same error. Once I have this fixed I will have a pretty much complete emulationstation.