wiki:RemovingABuildChroot
  1. Run VG=/dev/blah scripts/clean-schroots as root to make sure that the build chroot is not mounted, substituting the name of the volume group for blah.
  1. Look in /etc/schroot/chroot.d/ and delete the file corresponding to the chroot.
  1. Run lvchange -an blah/chrootname substituting the name of the volume group for blah and the chroot name for chroot. Example: lvchange -an dink/gutsy-i386-sbuild
  1. Run lvremove blah/chrootname