Upgrading libc6 on lenny leads to unusable system

[Mich Lanners <mlan@cpu.lu>]

Dear list,

I'm struggling with a problem I have a hard time fixing myself.

I'm running lenny originally installed form a weekly-build netinst. Two
days ago, the automatic update thingy suggested upgrading a few
packages, among them libc6 (from 2.6-2 to 2.6.1-1)

Problem is, the installation of libc6 failed, and since then all
programs just segfault.

I have tried a number of rescue operations, but it's not easy:
- dpkg --root= doesn't work here, because the pre/post scripts are run
  in the (broken) chroot environment and also segfault,
- I've tried to copy all files used by /bin/bash from a known good
  system (i.e. the binary and all libs reported by ldd), but still no
  luck: it keeps segfaulting.
- It's hard to see where it segfaults: debuggers in the installation
  segfault, those outside see only the chroot process.
- I can't simply reinstall from the installer over the existing system
  for the same reason: the installer chroots inside /target and there
  everything just segfaults.

I've also tried the radical way of removing /lib, /bin, /etc/ld.so*.

That seemed to work but a subsequent upgrade brought me to the same
point again. Luckily I was able to note down the exact error messages:


Preparing to replace libc6 2.6-2 (using .../libc6_2.6.1-1_i386.deb) ...
Unpacking replacement libc6 ...
Setting up libc6 (2.6.1-1)
Installing new version of config file /etc/init.d/glibc.sh ...
/var/lib/dpkg/info/libc6.postinst: line 320: 23349 Segmantation Fault
dpkg --compare-versions $preversion lt 2.3.5-1
/var/lib/dpkg/info/libc6.postinst: line 320: 23350 Segmentation Fault    iconvconfig
/var/lib/dpkg/info/libc6.postinst: line 20: 23351 Segmentation Fault     update-rc.d "$@" >/dev/null
dpkg: error processing libc6 (--configure):
 subprocess post-installation script returned error exit status 139



I've found no bug that looks related.

Did anyone experience this? Should I file a bug?

What is the best way out of this?


Thanks, and cheers

michel

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