[[!comment format=mdwn username="picca" subject="comment 1" date="2015-09-29T12:35:27Z" content=""" ok, so I created this property but it does not work sbuild :: System -> FilePath -> Property NoInfo sbuild system tarball = chroot `onChange` Tar.create chrootdir tarball where chroot = Chroot.debootstrapped system Debootstrap.BuilddD chrootdir chrootdir = \"/tmp/chroot\" it fails with this error message src/config.hs:167:3: Couldn't match expected type `Property x0' with actual type `Chroot.Chroot' In the first argument of `onChange', namely `chroot' In the expression: chroot `onChange` Tar.create chrootdir tarball What I understand it that onChange expect a Property instead of a Chroot. So what is the right way to tell propellor look at this chrootdir directory and create a tarball if its containt changed. """]]