*Created by: bartoszek* Current behavior is to append all `cache_dirs` to each line containing `(#)CacheDir` in `$working_dir/etc/pacman.conf` https://github.com/archlinux/devtools/blob/90ba07d9be2883cccb1dd42aa0c8f974a2ff055c/arch-nspawn.in#L111 Witch results in redundant entries appearing in `$working_dir/etc/pacman.conf` each time `arch-nspawn` is started. ```conf [options] CacheDir= /var/cache/pacman/pkg /var/cache/aur /var/cache/pacman/pkg/ /var/cache/aur ... ``` Beside producing extra entries if `pacman.conf` contains more then single `CacheDir=` line This behavior collides with `rw/ro` mount point logic producing unusable chroot environment. https://github.com/archlinux/devtools/blob/90ba07d9be2883cccb1dd42aa0c8f974a2ff055c/arch-nspawn.in#L89-L93 ```sh mount_args=(--bind=/var/cache/pacman/pkg --bind-ro=/var/cache/aur --bind-ro=/var/cache/pacman/pkg/ --bind-ro=/var/cache/aru ... ) ``` This produces container without writable cache on second `arch-nspawn` call. ```sh $arch-nspawn /tmp/roo $$mount|grep sd /dev/sdb3 on /var/cache/pacman/pkg type ext4 (rw,realtime,commit=60,data=ordered) /dev/sdb3 on /var/cache/aur type ext4 (ro,realtime,commit=60,data=ordered) $$touch /var/cache/pacman/pkg/test $$exit $arch-nspawn /tmp/roo $$mount|grep sd /dev/sdb3 on /var/cache/pacman/pkg type ext4 (rw,realtime,commit=60,data=ordered) /dev/sdb3 on /var/cache/pacman/pkg type ext4 (ro,realtime,commit=60,data=ordered) /dev/sdb3 on /var/cache/aur type ext4 (ro,realtime,commit=60,data=ordered) /dev/sdb3 on /var/cache/aur type ext4 (ro,realtime,commit=60,data=ordered) $$touch /var/cache/pacman/pkg/test touch: cannot touch '/var/cache/pacman/pkg/test/' : Read-only file system ```