mock-mount.sh -- compat script for bwrap in mock

mock-mount.sh

#!/bin/bash
set -euo pipefail

# This is a small compatibility script that ensures mock
# chroots are compatible with applications that expect / to
# be a mount point, such as bubblewrap.

cleanup() {
    for mnt in sys proc; do
        umount /mnt/mock-mount/$mnt
    done
    umount /mnt/mock-mount
    umount /mnt/mock-mount
}

trap cleanup EXIT

# The parent of mount in which we'll chroot can't be shared
# or pivot_root will barf. So we just remount onto itself,
# but make sure to make the first parent mount private.

mkdir -p /mnt/mock-mount
mount --bind / /mnt/mock-mount
mount --make-private /mnt/mock-mount
mount --bind /mnt/mock-mount /mnt/mock-mount
for mnt in proc sys; do
    mount --bind /$mnt /mnt/mock-mount/$mnt
done

chroot /mnt/mock-mount "$@"