Building rpms on F12 - buildroot overridden

[Chris]

Hi all,

I'm having a strange problem building an rpm on F12. Everything goes
fine until the build stage at which point my "BuildRoot:" parameter is
being ignored. Instead of building in the location I specified, it
always uses a directory called BUILDROOT.

For example, I expect that the build will occur in
"/tmp/rpmbuild.chris/BUILD/mypackage/" but it is trying to build in
"/tmp/rpmbuild.chris/BUILDROOT/mypackage-x.y-z.fc12.i386".
I put "echo %{buildroot}" into the %build section of the spec file and
it outputs that BUILDROOT path even though I've explicitly set the
BuildRoot variable at the top.

This path seems to be set in some default rpm configuration somewhere
since rpmbuild --showrc finds it, e.g.:

# rpmbuild --showrc | grep BUILDROOT
-14: _buildrootdir      %{_topdir}/BUILDROOT

But why doesn't the setting in my spec file override this? And what
the heck is BUILDROOT for? I thought we should just have BUILD, RPMS,
SOURCES, SPECS, and SRPMS directories.

Any suggestions gratefully received!

Regards, Chris.