未能满足Debian7的依赖

我把debian的dist-upgrade从7.8版本升级到了8.1版本。

然后我有一些旧的PHP编译器不得不恢复。

自从降级以来,我试图做一个远程升级

The following packages have unmet dependencies: coreutils : PreDepends: libacl1 (>= 2.2.51-8) but it is not going to be installed PreDepends: libattr1 (>= 1:2.4.46-8) but it is not going to be installed dpkg : PreDepends: tar (>= 1.23) but it is not going to be installed util-linux : Depends: tzdata (>= 2006c-2) but it is not going to be installed Depends: initscripts but it is not going to be installed Depends: debconf (>= 0.5) but it is not going to be installed or debconf-2.0 PreDepends: libblkid1 (>= 2.20.1) but it is not going to be installed PreDepends: libncurses5 (>= 5.5-5~) but it is not going to be installed PreDepends: libtinfo5 but it is not going to be installed PreDepends: libuuid1 (>= 2.16) but it is not going to be installed E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages. 

你知道什么可能会导致这个问题吗?

谢谢。