Code review comment for lp:~snappy-dev/livecd-rootfs/core_update

This fails unfortunately with:
"""
[2015-03-25 14:19:26] lb_binary_hooks
P: Begin executing hooks...
+ echo I: Remove unneeded files from /usr/share/doc
I: Remove unneeded files from /usr/share/doc
+ find binary/boot/filesystem.dir/usr/share/doc -depth -type f ! -name copyright
+ xargs rm -f
+ + findxargs binary/boot/filesystem.dir/usr/share/doc rmdir
 -empty
+ find binary/boot/filesystem.dir/usr/share/doc -type f -exec gzip -9 {} ;
+ echo I: Remove man/info pages
I: Remove man/info pages
+ rm -rf binary/boot/filesystem.dir/usr/share/man binary/boot/filesystem.dir/usr/share/groff binary/boot/filesystem.dir/usr/share/info binary/boot/filesystem.dir/usr/share/lintian binary/boot/filesystem.dir/usr/share/linda binary/boot/filesystem.dir/var/cache/man
+ echo I: Removing /var/lib/apt/lists/*
I: Removing /var/lib/apt/lists/*
+ find binary/boot/filesystem.dir/var/lib/apt/lists/ -type f
+ xargs rm -f
+ echo I: Removing /var/cache/apt/*.bin
I: Removing /var/cache/apt/*.bin
+ rm -f binary/boot/filesystem.dir/var/cache/apt/pkgcache.bin binary/boot/filesystem.dir/var/cache/apt/srcpkgcache.bin
+ echo I: Creating warning to use snappy when apt-get is used
I: Creating warning to use snappy when apt-get is used
+ PREFIX=binary/boot/filesystem.dir
+ mkdir -p binary/boot/filesystem.dir/usr/local/bin
+ cat
+ chmod 755 binary/boot/filesystem.dir/usr/local/bin/no-apt
+ ln -s no-apt binary/boot/filesystem.dir/usr/local/bin/apt
+ ln -s no-apt binary/boot/filesystem.dir/usr/local/bin/apt-cache
+ ln -s no-apt binary/boot/filesystem.dir/usr/local/bin/apt-get
I: Moving kernel into device tarball
cp: with --parents, the destination must be a directory
Try 'cp --help' for more information.
E: config/hooks/500-move-kernel-to-device-tar.binary failed (exit non-zero). You should check for errors.
P: Begin unmounting filesystems...
P: Saving caches...
Reading package lists...
Building dependency tree...
Reading state information...
Traceback (most recent call last):
  File "/usr/share/launchpad-buildd/slavebin/buildlivefs", line 198, in main
    builder.build()
  File "/usr/share/launchpad-buildd/slavebin/buildlivefs", line 159, in build
    self.run_build_command(["lb", "build"], env=base_lb_env)
  File "/usr/share/launchpad-buildd/slavebin/buildlivefs", line 108, in run_build_command
    self.chroot(["/bin/sh", "-c", command], echo=echo)
  File "/usr/share/launchpad-buildd/slavebin/buildlivefs", line 89, in chroot
    "/usr/bin/sudo", "/usr/sbin/chroot", self.chroot_path] + args)
  File "/usr/lib/python2.7/subprocess.py", line 511, in check_call
    raise CalledProcessError(retcode, cmd)
""""