apt-get update/upgrade coredumps (apt-cache actually segfaults)

[Roberto Nibali]

> I've collected a bt for your viewing pleasure (probably not very 
> helpful):
> 
> (no debugging symbols found)
> Core was generated by `apt-get update'.
> Program terminated with signal 11, Segmentation fault.
> #0  0xb7d02c53 in strlen () from /lib/tls/i686/cmov/libc.so.6
> (gdb) bt
> #0  0xb7d02c53 in strlen () from /lib/tls/i686/cmov/libc.so.6
> #1  0xb7e8a186 in std::string::compare () from /usr/lib/libstdc++.so.6
> #2  0xb7f86a27 in debPackagesIndex::FindInCache ()
>    from /usr/lib/libapt-pkg-libc6.4-6.so.3.51
> #3  0xbff1b2ac in ?? ()
> #4  0x00000000 in ?? ()
> (gdb)
> 
> The following is a bit special, but might not be influencial to this 
> core dumping behaviour:
> 
> Ign http://download.skype.com stable/non-free Translation-en_US
> 99% [5 Translation-en_US bzip2 0] [Release gpgv 19613] [Waiting for 
> headers] [Wbzip2: (stdin) is not a bzip2 file.

Ok, it does not have anything to do with this. stracing apt-cache shows:

root at laphish2:~# strace -v -F -f -q apt-cache show apt 2>&1 | tail -5
fstat64(3, {st_dev=makedev(3, 3), st_ino=1242814, st_mode=S_IFREG|0644, 
st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=18656, 
st_size=9602189, st_atime=2006/10/31-13:21:12, 
st_mtime=2006/10/31-13:21:19, st_ctime=2006/10/31-13:21:19}) = 0
mmap2(NULL, 9602189, PROT_READ, MAP_SHARED, 3, 0) = 0xb7212000
stat64("/var/lib/apt/lists/ch.archive.ubuntu.com_ubuntu_dists_edgy_main_binary-i386_Packages", 
{st_dev=makedev(3, 3), st_ino=1195052, st_mode=S_IFREG|0644, st_nlink=1, 
st_uid=0, st_gid=0, st_blksize=4096, st_blocks=10752, st_size=5491154, 
st_atime=2006/10/25-19:04:23, st_mtime=2006/10/25-19:04:23, 
st_ctime=2006/10/26-08:13:51}) = 0
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV (core dumped) +++

root at laphish2:~# ltrace -C -S -f -i apt-cache show apt 2>&1 | tail -5
[0xb7f12410] SYS_fstat64(3, 0xbfd2a660, 0xb7d11ff4, 3, 0x805d8c8) = 0
[0xb7f12410] SYS_mmap2(0, 0x92848d, 1, 1, 3)     = 0xb71ae000
[0xb7f12410] SYS_stat64(0x805dde4, 0xbfd2a670, 0xb7d11ff4, 3, 
0xbfd2a77c) = 0
[0xb7c4ec53] --- SIGSEGV (Segmentation fault) ---
[0xffffffff] +++ killed by SIGSEGV +++

Highly irritating!

Would removing the cache files help? If so, which files should I remove?
-- 
echo 
'[q]sa[ln0=aln256%Pln256/snlbx]sb3135071790101768542287578439snlbxq' | dc