最近 ubuntu apt 总是尝试升级 libnvidia-common 包但没有效果，所以我查询这个包并发现 2 个完全相同的来源，一个来自 canonical，另一个来自 nvidia cuda ppa：
$ apt show libnvidia-common-450 -a
Package: libnvidia-common-450
Version: 450.36.06-0ubuntu1
Priority: optional
Section: non-free/libs
Source: nvidia-graphics-drivers-450
Maintainer: Ubuntu Core Developers <[email protected]>
Installed-Size: 35.8 kB
Provides: libnvidia-common
Replaces: libnvidia-common, libnvidia-gl-450 (<< 390.25-0ubuntu2~)
Download-Size: 10.2 kB
APT-Sources: http://developer.download.nvidia.com/compute/cuda/repos/ubuntu1804/x86_64 Packages
Description: Shared files used by the NVIDIA libraries
This package provides a set of files that are required by the NVIDIA
libraries.
Package: libnvidia-common-450
Version: 450.36.06-0ubuntu1
Status: install ok installed
Priority: optional
Section: non-free/libs
Source: nvidia-graphics-drivers-450
Maintainer: Ubuntu Core Developers <[email protected]>
Installed-Size: 35.8 kB
Provides: libnvidia-common
Breaks: libnvidia-gl-450 (<< 390.25-0ubuntu2~)
Replaces: libnvidia-common, libnvidia-gl-450 (<< 390.25-0ubuntu2~)
Homepage: http://www.nvidia.com
Download-Size: unknown
APT-Manual-Installed: no
APT-Sources: /var/lib/dpkg/status
Description: Shared files used by the NVIDIA libraries
This package provides a set of files that are required by the NVIDIA
libraries.
$ aptitude show libnvidia-common-450
Package: libnvidia-common-450
Version: 450.36.06-0ubuntu1
State: installed (450.36.06-0ubuntu1), upgrade available (450.36.06-0ubuntu1)
Automatically installed: yes
Priority: optional
Section: non-free/libs
Maintainer: Ubuntu Core Developers <[email protected]>
Architecture: all
Uncompressed Size: 35.8 k
Replaces: libnvidia-common, libnvidia-gl-450 (< 390.25-0ubuntu2~)
Provides: libnvidia-common
Description: Shared files used by the NVIDIA libraries
This package provides a set of files that are required by the NVIDIA libraries.
那么我该如何避免这种情况呢？