I tried to do an update/upgrade of a stable system, and got a bunch of broken dependencies; 642 packages not upgraded, and a ton of these:
"insserv: warning: script 'S21initrd-tools.sh' missing LSB tags and overrides"
...
insserv: exiting now without changing boot order!
update-rc.d: error: insserv rejected the script header
dpkg: error processing udev (--configure):
subprocess installed post-installation script returned error exit status 1

and things like this:
dpkg: dependency problems prevent configuration of libice6:
libice6 depends on x11-common; however:
Package x11-common is not configured yet.
...
dpkg: dependency problems prevent configuration of xdm:
xdm depends on libxaw7; however:
Package libxaw7 is not configured yet.
xdm depends on libxmu6; however:
Package libxmu6 is not configured yet.
xdm depends on libxt6; however:
Package libxt6 is not configured yet.
xdm depends on x11-xserver-utils; however:
Package x11-xserver-utils is not configured yet.
dpkg: error processing xdm (--configure):
dependency problems - leaving unconfigured

ending in failure:
dpkg: too many errors, stopping
Errors were encountered while processing:
cron
udev
console-common
keyboard-configuration
x11-common
libice6
libsm6
libxt6
libaudio2
libxmu6
libxaw7
libxss1
libxtst6
mailgraph
anacron
logrotate
...
Processing was halted because there were too many errors.

I then tried an upgrade-dist, thinking it might be good to move to most recent versions, but that just dug the hole deeper:
Setting up initscripts (2.88dsf-41+deb7u1) ...
insserv: warning: script 'K02hotplug-net' missing LSB tags and overrides
...
insserv: warning: script 'hotplug-net' missing LSB tags and overrides
insserv: There is a loop between service munin-node and modutils if stopped
insserv: loop involving service modutils at depth 2
insserv: loop involving service munin-node at depth 1
insserv: Stopping modutils depends on munin-node and therefore on system facility `$all' which can not be tr
ue!
insserv: exiting now without changing boot order!
update-rc.d: error: insserv rejected the script header
dpkg: error processing initscripts (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
initscripts

I have had problems like this several times in the past years with Debian, and sometimes had to start over from a clean install, and re-do all installation packages, configuration, setup, etc - a real pain.

Is there any hope of recovery for this system, and any way to avoid this sort of update failures?

(cat /etc/issue: Debian GNU/Linux 6.0 )

With dependency errors, my first thought goes to the sources.list. Do you have sources from anywhere other than Debian Stable and backports, or have you installed any packages from source that use more recent libraries than those on your system?

Nope.
I run a very simple standard system. :-)

Nope.

You USED to run a very simple OLDstable system with "stable" in your sources rather than "squeeze" so you have "surprise upgraded" (partially) to wheezy.

This is a bad idea for reasons you are now discovering.

Read the wheezy release notes about upgrading from squeeze and what you should have done first (along with the apt-get and dpkg man pages which you will likely need to know) and see if you can battle your way through the borked upgrade to wheezy.

Otherwise - reinstall.

3 members found this post helpful.

apt-get clean
apt-get update
apt-get upgrade
apt-get dist-upgrade

sorry for repost

@Eddy1 - yes, that's just what I did.

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