Package building in clean/chroot environment

[Brian Candler]

Are there are any tools for building FreeBSD packages in a chroot cleanroom
environment?  This is so that I can be sure that all dependencies are
properly declared, and so that I can be sure that the built binaries don't
accidentally link to libraries which happen to be available on my build
system but won't be available on the target system (oh, the joy of autoconf)

I found the documentation for pointyhat:
http://www.freebsd.org/doc/en/articles/portbuild/article.html
but I'd rather not go as far as building a whole pointyhat cluster :-)

What I'm thinking of is a utility which will:
- create a chroot environment (easy, just untar distribution)
- build a chosen port, pulling in dependencies as packages where possible,
  otherwise building dependencies as packages too
- keep the built packages and distfiles locally, to speed up future builds
- reset the chroot environment back to its pristine state
- if possible run as non-root

I use this for Linux/RPM: http://thomas.apestaart.org/projects/mach/
but was wondering if there is something similar for the FreeBSD ports world.

My requirement is to be able to build safe binaries on a central box for
distribution out to FreeBSD cluster nodes, so they don't have to be compiled
separately on each node.

Thanks,

Brian.