升级到版本20没有完成。转到读取状态信息,然后停止。我试图通过终端和更新管理器进行更新--结果不会改变(root@dev-pc:/home/develop# sudo /usr/lib/ubuntu-release-upgrader/check-new-release-gtk
/usr/lib/ubuntu-release-upgrader/check-new-release-gtk:30: PyGIWarning: Gtk was imported without specifying a version first. Use gi.re