chroot to X-apps= can't open display 0.0 Error

Do you have a question? Post it now! No Registration Necessary.  Now with pictures!

I won't name other distributions, since certain tribalists get
hysterical when promiscuity is mentioned, but in 2002 my main
X-app was installed to distroA.  Then later when distroB was installed,
AFAIR, I just mounted distroA and patched the run-script to point
to distroA. And the same again when installing distroC in 2011.

Since I don't like the bloated browser of distroC , I was now able to
patch distroA's opera runscript by prepending, and appending, thus:-
# patch /mnt/FC1/usr/bin/opera to run script from slak13 to call Mandrake.

mount --bind /dev/shm /mnt/hdc6/dev/shm
mount --bind /home /mnt/hdc6/home
mount --bind /proc /mnt/hdc6/proc   <--these 3 lines added

# Location of the Opera binary
OPERA=/mnt/hdc6/usr/X11R6/bin/opera   <--distroA

if test ! -f $; then
    echo "The Opera binary is not located at \"$\"."
    echo "Please modify the wrapper script at \"\"."
    exit 1
$ "$"

echo 'MUST umount BIND on exit !!'

umount /mnt/hdc6/proc  <-- these 4 lines don't 'balance'
umount /mnt/hdc6/home
umount /mnt/hdc6/dev/shm ; sleep 4 <--? copies from ?
umount /mnt/hdc6/dev

It works OK.  But all other X-app whach I try to similarly
chroot-to, give:  can't open display 0.0 Error,
also when I `mount --bind` /proc and /dev/

Is this because the chrooted-distro hasn't initialise
its X-system, via *its* `startx`, or what?

Then why do these 2 other X-apps run OK?

== TIA

Site Timeline