This only matter for the status display at the end of configure step.
Now it looks like:
RPM macros dir: /usr/lib/rpm/macros.d
polkitpkladir = join_paths(localstatedir, 'lib/polkit-1/localauthority/10-vendor.d')
varlogdir = join_paths(localstatedir, 'log')
xinitrcdir = join_paths(sysconfdir, 'X11/xinit/xinitrc.d')
-rpmmacrosdir = get_option('rpmmacrosdir')
+rpmmacrosdir = join_paths(prefixdir, get_option('rpmmacrosdir'))
modprobedir = join_paths(rootprefixdir, 'lib/modprobe.d')
# Our own paths