Comment 2 for bug 924079

Reproduces with 'apt-get dist-upgrade' from a clone of your state. Debug::pkgPackageManager=true says:

SmartConfigure libtinfo5
  DepAdd: libtinfo5
SmartConfigure libtinfo5
  DepAdd: libtinfo5
    DepAdd: libc6
      DepAdd FAILS on: libc6
    DepAdd FAILS on: libtinfo5
PreDepends order for libncurses5
Found ok package multiarch-support
PreDepends order for libncurses5
Trying to SmartConfigure libtinfo5
SmartConfigure libtinfo5
SmartConfigure libtinfo5
  DepAdd: libtinfo5
    DepAdd: libc6
      DepAdd FAILS on: libc6
    DepAdd FAILS on: libtinfo5
PreDepends order for libncurses5
Found ok package multiarch-support
PreDepends order for libncurses5
Trying to SmartConfigure libtinfo5
SmartConfigure libtinfo5
  DepAdd: libtinfo5
    DepAdd: libc6
      DepAdd FAILS on: libc6
    DepAdd FAILS on: libtinfo5
E: Couldn't configure pre-depend libtinfo5 for libncurses5, probably a dependency cycle.

It may be worth noting that this is amd64, and libc6:i386 is being newly installed here.