Не удается установить libstdc ++

Я использую Ubuntu 15.04, вот что у меня есть:

 ...
      libstdc++6-4.9-dbg-arm64-cross : Conflicts: libstdc++6-4.8-dbg-arm64-cross but 4.8.4-1ubuntu15cross0.15 is to be installed
      libstdc++6-4.9-dbg-armel-cross : Conflicts: libstdc++6-4.7-dbg-armel-cross but 4.7.4-2ubuntu1cross1.86 is to be installed
      libstdc++6-4.9-dbg-armhf-cross : Conflicts: libstdc++6-4.7-dbg-armhf-cross but 4.7.4-2ubuntu1cross1.86 is to be installed
                                       Conflicts: libstdc++6-4.8-dbg-armhf-cross but 4.8.4-1ubuntu10cross0.15 is to be installed
      libstdc++6-4.9-dbg-powerpc-cross : Conflicts: libstdc++6-4.8-dbg-powerpc-cross but 4.8.4-1ubuntu10cross0.18 is to be installed
      libstdc++6-4.9-dbg-ppc64el-cross : Conflicts: libstdc++6-4.8-dbg-ppc64el-cross but 4.8.4-1ubuntu10cross0.7 is to be installed
     E: Unable to correct problems, you have held broken packages.