Defines for detecting build OS?

[Greg_Swift at aotx.uscourts.gov]

> For EPEL (the extra packages for enterprise linux) I was told the build
> system provides the macro definitions.  The ones i've seen are (basing on
> 5, change accordingly):
>
> %rhel 5
> %dist .el5
>
> I recently put in a bug requesting the same macros.dist file for any RHEL
> they would be willing to add it to
> (https://bugzilla.redhat.com/show_bug.cgi?id=481023).

I guess it also would have been helpful to state that if you need them on
your system you can just create that /etc/rpm/macros.dist file or for
single shot builds you can do this:

rpm --define "dist .el5" --define "rhel 5" -ba my.spec

-greg