To (try to) solve the previous issue, I set up in the setup.cfg
MAXDEPTH = 1
USE_LOCATE = False
HOME_BOOST = '/usr'
LIBNAME_BOOST = 'libboost_python312'
So, in my opinion it should go one folder down from /usr, which is /usr/lib, and then stop there. But no, the script still goes on folder /usr/lib/cmake (see line 553 and 562 of the putput file)
Another clue is variable HOME_BOOST. At the beginning, it contains "/usr" (see line 22) but later, at tfel installation script, it is empty (see line 224).
So, I think that tfel installer does not care about what it is in setup.cfg. A developer might check it and confirm (or deny 😉