Bug#840372: debootstrap: second-stage fails within systemd-nspawn: proc already mounted

[Hideki Yamane <henrich@iijmio-mail.jp>]

control: tags -1 +confirm
control: tags -1 +patch

On Tue, 11 Oct 2016 03:50:51 +0200 linus.luessing@c0d3.blue wrote:
> $ sudo systemd-nspawn --bind /usr/bin/qemu-x86_64-static -D "./.amd64/" /bin/bash -c "mkdir /tmp/proc; mount --move /proc /tmp/proc; /debootstrap/debootstrap --second-stage"
> ~~~~
> 
> So it looks like systemd-nspawn already took care of mounting /proc and
> debootstrap fails when trying to do the same? Maybe debootstrap could
> just skip mounting /proc if this mount is already present?

 Here's a proposed patch.


diff --git a/functions b/functions
index 005b007..10938fe 100644
--- a/functions
+++ b/functions
@@ -1133,12 +1133,15 @@ setup_proc () {
                umount_on_exit /proc
                umount_on_exit /proc/bus/usb
                umount "$TARGET/proc" 2>/dev/null || true
-               in_target mount -t proc proc /proc
-               if [ -d "$TARGET/sys" ] && \
-                  grep -q '[[:space:]]sysfs' /proc/filesystems 2>/dev/null; then
-                       umount_on_exit /sys
-                       umount "$TARGET/sys" 2>/dev/null || true
-                       in_target mount -t sysfs sysfs /sys
+               # if systemd-nspawn is used at second-stage, it already treats /proc and so on
+               if [ ! -n "$(ls -A /proc)" ]; then
+                       in_target mount -t proc proc /proc
+                       if [ -d "$TARGET/sys" ] && \
+                          grep -q '[[:space:]]sysfs' /proc/filesystems 2>/dev/null; then
+                               umount_on_exit /sys
+                               umount "$TARGET/sys" 2>/dev/null || true
+                               in_target mount -t sysfs sysfs /sys
+                       fi
                fi
                on_exit clear_mtab
                ;;