Bug#420667: libc6 breaks bash, renders all compiles unusable

[David Baron <d_baron@012.net.il>]

Package: libc6
Version: 2.5-2
Severity: critical
Justification: breaks unrelated software

1. Upgrade -- balks at symlinks in /usr/lib, asks user to remove them. BAD
BAD BAD!
2. Once these removed, installs. Bash is now unusable--problem is in calls
from bashrc, bash.bashrc, et al. bash -norc, sh (not login) work. 
3. The libc.so.6 synlink it kicked at is replaced. Reinstall will again
balk.
4. The other symlinks are needed by ld when building dependent programs!
5. Once replaced, builds procede but all built programs segfault.

-- System Information:
Debian Release: lenny/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (650, 'testing'), (500, 'stable')
Architecture: i386 (i686)

Kernel: Linux 2.6.20-davidb (SMP w/1 CPU core; PREEMPT)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/bash

-- no debconf information