I realize now that the problem is the line

    test -f lua/Makefile && cd lua && $(MAKE) install || true

in the target "install-data-local", in bindings/Makefile.am. It forces
execution of bindings/lua/Makefile independently of lua being found or
not. I added that line in my first patch, following perl, python and
ruby build style, but it's not needed after I switched to automake. The
make recursion is controlled by SUBDIRS, which will only contain "lua"
if BUILD_LUA is true.

-- Fidelis Assis

git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@1645 a5681a0c-68f1-0310-ab6d-d61299d08faa