It turns out that a surprising number of common packages use lua
scripts in RPM files, and not having lua can lead to obscure failures.
The propagatedBuildInputs stuff makes the librpm stuff more useful,
since some of its headers didn't work without extra buildInputs before.
Currently, building RPM with `python = python3` causes this:
checking for a Python interpreter with version >= 2.6... python3
checking for python3... /nix/store/dykqxnrwiz9drlcv2wy8lpvl3xvklx0g-python3-3.4.3/bin/python3
checking for python3 version... 3.4
checking for Python.h... yes
checking for library containing Py_Main... no
configure: error: missing python library
That comes from this snippet in configure.ac:
AC_SEARCH_LIBS([Py_Main],[python${PYTHON_VERSION} python],[
WITH_PYTHON_LIB="$ac_res"
],[AC_MSG_ERROR([missing python library])
])
So it's looking for (e.g) `libpython3.4.so` wheras we have `libpython3.4m.so`.
Patching the configure script to match seems to make that work (although
I don't really understand what the heck is this 'm' business about).