smime.p7s
Description: S/MIME Cryptographic Signature
I further investigated this error and it seems it has to do with my
system already using the new directory structure, where /lib is
symlinked to /usr/lib and your packages tries to place an aditional
symlink in /usr/lib/x86_64-linux-gnu/libpng12.so.0 which would then link
to itself. However, /usr/lib is never accessed when loading
x86_64-linux-gnu libraries, so it should be save to remove this part
from the package.