Hi Jure, this patch usually takes care of the "m" for Python 3: https://github.com/easybuilders/easybuild-easyconfigs/blob/master/easybuild/easyconfigs/b/Boost/Boost-1.65.1_fix-Python3.patch see e.g. https://github.com/easybuilders/easybuild-easyconfigs/blob/master/easybuild/easyconfigs/b/Boost/Boost-1.66.0-intel-2018a-Python-3.6.4.eb where it is referenced.
Bart
