Parece que você está tentando instalar um Debian 8 libc6 (2.19-11) em um sistema Debian 7 (2.13-38 + deb7u8). Verifique seu /etc/apt/sources.list para quaisquer entradas estranhas.
Eu tentei instalar MIME :: Base64 com cpanm, o que me dá o erro que sys / types.h está faltando. Eu então tento instalar o libc6-dev que falha com a mensagem de erro
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
libc6-dev : Depends: libc6 (= 2.13-38+deb7u8) but 2.19-11 is to be installed
Depends: libc-dev-bin (= 2.13-38+deb7u8)
E: Unable to correct problems, you have held broken packages.
Espero que alguém conheça uma solução e possa me ajudar