pkg_comp is a small utility designed to build packages inside a clean chroot tree. Some ideas about what to use it for (taken from manpage): * Build packages for other system versions. For example, build packages for NetBSD 1.5 while you are running NetBSD current. * Build packages using different options than your current system like changing the threading library, COPTS, placement of configuration files, etc. * Debug the build process of a package, checking if buildlinks work properly. * Avoid autoconf's side effects by keeping a separate chroot for each project, like one for GNOME2 and another one for KDE3. * Schedule builds of package sets for several different machines.