(gdb) bt
#0  0x4f904c03 in strlen () from /lib/tls/i686/cmov/libc.so.6
#1  0x414b2326 in std::string::compare () from /usr/lib/libstdc++.so.6
#2  0xb7f982e7 in debPackagesIndex::FindInCache (this=0x80ae3e8, Cache=@0xbf8796f4)
    at /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/basic_string.h:2200
#3  0xb7f63a0c in CheckValidity (CacheFile=<value optimized out>, Start={_M_current = 0x80b10d0}, End={_M_current = 0x80b11ac}, OutMap=0xbf879a14)
    at pkgcachegen.cc:689
#4  0xb7f63fb3 in pkgMakeStatusCache (List=@0xbf879950, Progress=@0xbf8799a4, OutMap=0xbf879a14, AllowMem=false) at pkgcachegen.cc:824
#5  0xb7f5a48a in pkgCacheFile::BuildCaches (this=0xbf879a14, Progress=@0xbf8799a4, WithLock=false) at cachefile.cc:70
#6  0x08058470 in DoUpdate (CmdL=@0xbf87a254) at apt-get.cc:90
#7  0xb7f244bb in CommandLine::DispatchArg (this=0xbf87a254, Map=0xbf87a1dc, NoMatch=true) at contrib/cmndline.cc:340
#8  0x0804e4bb in main (argc=2, argv=0xbf87a314) at apt-get.cc:2772