mame2016 fails to build in Linux and solution

[bugalo]

mame2016 fails to build in Linux, when using the following command:
NOCLEAN=./libretro-build.sh mame2016

giving the following error:
cc1plus: all warnings being treated as errors

This is because gmake is using Makefile and not Makefile.libretro. This can be fixed by editing the file rules.d/core-rules.sh, line 980, and replacing libretro_mame2016_makefile="Makefile" with libretro_mame2016_makefile="Makefile.libretro" and adding afterwards libretro_mame2016_build_makefile=Makefile.libretro.

mame2016 will then build just fine, provided that python2 is installed. I don't have python2 installed, so I get the following error:
Python is not available in path. Stop.
This error can also be fixed by modifying Makefile.libretro and adding, after line 114 the following two lines:

else ifeq ($(platform), unix)
	PYTHON_EXECUTABLE = python

The build process will then use the available Python.