As of version 3.9.3, python stopped bundling some autoconf m4 macros and started relying on the 'autoconf-archive' package being installed and in standard system paths. Yes, in a minor release update, really. diff -wpruN --no-dereference '--exclude=*.orig' a~/configure.ac a/configure.ac --- a~/configure.ac 1970-01-01 00:00:00 +++ a/configure.ac 1970-01-01 00:00:00 @@ -16,6 +16,8 @@ AC_PREREQ([2.71]) AC_INIT([python],[PYTHON_VERSION],[https://github.com/python/cpython/issues/]) +AC_CONFIG_MACRO_DIRS([/opt/ooce/autoconf-archive/share/aclocal]) + m4_ifdef( [AX_C_FLOAT_WORDS_BIGENDIAN], [],