On Sun, 02 Dec 2018 at 21:04:55 +0100, Marc Haber wrote: > The next debhelper change might choose to give / instead of /usr as a > target directory by default, moving hundreds of megabytes from /usr to / > over time.
I don't think anyone is proposing that. There's no reason why it would be preferred over the merged /usr arrangement implemented in both usrmerge and debhelper --merged-usr, which is the same as is implemented in some other Linux distributions (e.g. Fedora): /usr is a real directory, and /bin, /sbin, /lib* are symlinks to the corresponding directories in /usr. Unifying /usr with / by making /usr a symlink to / is the opposite of the merged /usr arrangement that is currently implemented. The Debian hurd-i386 port did try having a /usr -> / symlink a few years ago as a simplification, but it has all the same transitional issues as merged /usr, with fewer advantages, which makes it unappealing. The purpose of merged /usr is to group together all the static files (/bin, /sbin, /lib* and the current /usr), which are more similar than they are diferent, into one place that can be a (maybe read-only) mount point (/usr). If you do the opposite, your root filesystem is still a mixture of mutable files in /etc and static files in /bin, /sbin, /lib*, so you haven't gained as much simplification as you would have had with merged /usr. (You talk about "default target directories", but there is nothing so elaborate: debootstrap --merged-usr simply unpacks packages into a chroot that already contains the symbolic links like /bin -> /usr/bin, instead of into an empty chroot.) smcv