pi@raspberrypi /var/lib/dpkg/info $ sudo apt-get install libc6 --reinstall
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 38 not upgraded.
Need to get 0 B/4,098 kB of archives.
After this operation, 0 B of additional disk space will be used.
Preconfiguring packages ...
dpkg: warning: files list file for package 'libc6:armhf' missing; assuming package has no files currently installed
(Reading database ... 60842 files and directories currently installed.)
Preparing to replace libc6:armhf 2.13-37+rpi1 (using .../libc6_2.13-37+rpi1_armhf.deb) ...

A copy of the C library was found in an unexpected directory:
  '/lib/arm-linux-gnueabihf/libc-2.13.so'
It is not safe to upgrade the C library in this situation;
please remove that copy of the C library or get it out of
'/lib/arm-linux-gnueabihf' and try again.

dpkg: error processing /var/cache/apt/archives/libc6_2.13-37+rpi1_armhf.deb (--unpack):
 subprocess new pre-installation script returned error exit status 1
Errors were encountered while processing:
 /var/cache/apt/archives/libc6_2.13-37+rpi1_armhf.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)