I’m not sure what the overall status of this bug is, so I will leave the versions as they are. Are the three comments from 2013 relevant, and is there anything I can do to help? The Python 2 code already unconditionally adds -IInclude (see Issue 786737), and does not use BASECPPFLAGS. I think it would better to remove Trent’s code, as in unused-flags.patch. Python 3 also has this unconditional -IInclude, so maybe we can eliminate one of them in Python 3? gcc -pthread -c -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -Werror=declaration-after-statement -IObjects -IInclude -IPython -I. -IInclude -I../Include -DPy_BUILD_CORE -o Python/Python-ast.o Python/Python-ast.c