/*! \page multiplebuilds Multiple build areas

It is possible to run several RPM builds on the same machine using
separate RPM databases.  On my build machine I have several build
areas which all run builds at the same time.  The builds do not
interfere with each other.  Each build behaves as if it was running on
its own machine and no build area knows about the RPM database which
actually configures the machine.

First, setup a "topdir" in a prefix other then where RPM is
installed.  You will need to make the directories.  They need to be
writable by the account which will do the building, typically they
are owned by the buildmaster account and set to permissions
755.

\verbatim
        BUILD RPMS SOURCES SPECS SRPMS
\endverbatim

Next, you will need to decide where the database files live. I suggest
putting them in a separate directory under "topdir".  I call my
directory DB and it has the same owner and permissions as the other
directories.

Each separate build area needs a rpmrc and macro configuration file. This
will need to specify the new topdir and dbpath.  If you will be building
the same packages in different work areas you will also need to specify a
tmppath into the topdir.  I suggest either making tmppath be the same as
the BUILD directory or adding another directory called BUILDROOT for it
in the topdir.

Keeping track of the correct rpmrc for each build area can be
difficult.  To make my life easier I make a small shell script with the
topdir hard coded inside:

\verbatim
        #!/bin/sh
        /bin/rpm --rcfile /topdir/rpmrc "$@"
        exit $?
\endverbatim

I call the shell script rpm and it lives in the topdir.  Each time I
wish to use a particular build area I just ensure that the build area
is first in my path so that when I run "rpm" I get the regular rpm
binary but I am using the local build areas rpmrc.

*/