Instead of overriding "build_ext.build_extensions()" in "old_build_ext", which works differently for parallel and sequential builds, override only "check_extensions_list()", which gets called by it at the beginning.
Instead of overriding "build_ext.build_extensions()" in "old_build_ext", which works differently for parallel and sequential builds, override only "check_extensions_list()", which gets called by it at the beginning.

scoder/cython,scoder/cython,scoder/cython,da-woods/cython,cython/cython,da-woods/cython,cython/cython,da-woods/cython,scoder/cython,cython/cython,da-woods/cython,cython/cython