[Pkg-sysvinit-devel] Unexpected problem with /etc/mtab -> /proc/mounts

[Petter Reinholdtsen]

When testing the new sysvinit package, I just discovered a problem
with this change:

  * Use /proc/mounts instead of /etc/mtab when unmounting  (Closes: #338801)

It make df very confused in a chroot:

minerva:/tmp# df
Filesystem           1K-blocks      Used Available Use% Mounted on
rootfs                10321208   9295900    501020  95% /
/dev/root.old         10321208   9295900    501020  95% /initrd
df: `/initrd/tmp': No such file or directory
/dev2/root2           10321208   9295900    501020  95% /
df: `/dev/.static/dev': No such file or directory
tmpfs                 10321208   9295900    501020  95% /dev
tmpfs                 10321208   9295900    501020  95% /dev/shm
/dev/intern_vg/var_lv
                      10321208   9295900    501020  95% /var
/dev/intern_vg/usr_lv
                      10321208   9295900    501020  95% /usr
/dev/intern_vg/home_lv
                      10321208   9295900    501020  95% /home
/dev/intern_vg/src_lv
                      10321208   9295900    501020  95% /usr/src
df: `/var/temp': No such file or directory
df: `/var/lib/postgres': No such file or directory
df: `/usr/src/chroot-sid/home': No such file or directory
df: `/usr/src/chroot-sid/proc': No such file or directory
minerva:/tmp#

Almost none of the mount points are available in the chroot.  Is this
how we want it?  Can we avoid replacing mtab when installing in a
chroot?  Do we want to?