Bug#745205: live-build: Recompressing initramfs breaks live installer

[Benjamin Moody <benjamin.moody@gmail.com>]

Package: live-build
Version: 3.0.5-1
Severity: normal

Dear Maintainer,

Setting LB_INITRAMFS_COMPRESSION to something other than 'gzip' causes
live-build to recompress the initramfs.  However, when this option is
used in combination with LB_DEBIAN_INSTALLER=live, the result is that
the installer will not rebuild the initramfs for the installed system.
This causes problems if you choose to use encryption when installing,
and possibly also if you choose to use LVM.

I think the reason for this problem is that update-initramfs checks to
see if the currently-installed initrd has a matching sha1sum in
/var/lib/initramfs-tools/.  Since live-build recompresses the initrd,
the sha1sum doesn't match, so update-initramfs refuses to touch it.

If I'm right about this, then it should be a simple matter for the
'chroot_hacks' script to update the sha1sum file after recompressing
the image.

Benjamin