apt-getでアップグレードを行おうとしたら,依存ループでひっかかる場合は以下の様に実行する.(でもaptitudeできちんと関係を眺めた方がいいんだけど)
# apt-get upgrade -o APT::Force-LoopBreak=true
ちなみにこんなエラーが出てた.
E: This installation run will require temporarily removing the essential package e2fsprogs due to a Conflicts/Pre-Depends loop. This is often bad, but if you re ally want to do it, activate the APT::Force-LoopBreak option. E: Internal Error, Could not early remove e2fsprogs