Relocatable RPM .spec question

> But I have a %post containing "%{_bindir}/foo" that isn't getting
> relocated properly.
> Its still looking for /usr/bin/foo instead of /home/ellson/usr/bin/foo.
>
> I tried "%{prefix}/bin/foo" but it still resolves to /usr/bin/foo

All %{...} macros are evaluated at RPM build time, so this won't work.

> Is there a variable set by the --prefix option that I can use in %post ?

Yes, environment variables. Using $RPM_INSTALL_PREFIX0 for the (first)
prefix should work.