我在我的 Ubuntu 16.04 服务器上犯了一个大错误。
我使用从源代码编译并安装了 Python 3.7.0 make altinstall，但没有包含我需要的所有核心依赖项，所以我打算删除它并安装预先打包的 deb。
但是为了删除它，我使用了此方法与 checkinstall 配合使用。我生成了一个 deb，这样我就可以删除原始安装创建的所有文件，但是对于 deb 的包名称，我只保留了默认的python。
现在，我已经安装了以下包：
$ sudo dpkg -l python
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-=====================================================-===============================-===============================-===============================================================================================================
ri python 3.7.0-1 amd64 Package created with checkinstall 1.6.2
这意味着我无法运行，dpkg -r python因为系统包依赖于刚刚调用的元包python：
$ sudo dpkg -r python
dpkg: dependency problems prevent removal of python:
python-ldb depends on python (<< 2.8).
python-ldb depends on python (>= 2.7~).
python-ldb depends on python (<< 2.8).
python-ldb depends on python (>= 2.7~).
python-ldb depends on python (<< 2.8).
python-ldb depends on python (>= 2.7~).
python-talloc depends on python (<< 2.8).
python-talloc depends on python (>= 2.7~).
python-talloc depends on python (<< 2.8).
python-talloc depends on python (>= 2.7~).
python-pyicu depends on python (>= 2.7).
python-pyicu depends on python (<< 2.8).
python-pyicu depends on python (>= 2.7).
python-pyicu depends on python (<< 2.8).
samba-common-bin depends on python.
samba depends on python (>= 2.7).
samba depends on python (<< 2.8).
samba depends on python (>= 2.7).
samba depends on python (<< 2.8).
iotop depends on python (>= 2.7.1-0ubuntu2).
iotop depends on python (<< 2.8).
iotop depends on python (>= 2.7.1-0ubuntu2).
iotop depends on python (<< 2.8).
python-cryptography depends on python (<< 2.8).
py
dpkg: error processing package python (--remove):
dependency problems - not removing
Errors were encountered while processing:
python
我无法再次安装默认版本的 python，因为我安装了错误的版本python：
$ sudo apt install python
Reading package lists... Done
Building dependency tree
Reading state information... Done
python is already the newest version (3.7.0-1).
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
iotop : Depends: python (< 2.8) but 3.7.0-1 is to be installed
python-acme : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-asn1crypto : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-certifi : Depends: python (< 2.8) but 3.7.0-1 is to be installed
python-cffi-backend : Depends: python (< 2.8) but 3.7.0-1 is to be installed
python-chardet : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-configparser : Depends: python (< 2.8) but 3.7.0-1 is to be installed
python-crypto : Depends: python (< 2.8) but 3.7.0-1 is to be installed
Depends: python:any (>= 2.7.5-5~)
python-cryptography : Depends: python (< 2.8) but 3.7.0-1 is to be installed
Depends: python:any (>= 2.7.5-5~)
python-dnspython : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-enum34 : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-funcsigs : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-future : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-idna : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-ipaddress : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-josepy : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-ldb : Depends: python (< 2.8) but 3.7.0-1 is to be installed
Depends: python:any (>= 2.7.5-5~)
python-mock : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-openssl : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-parsedatetime : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-pbr : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-pkg-resources : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-pyicu : Depends: python (< 2.8) but 3.7.0-1 is to be installed
python-requests : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-requests-toolbelt : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-rfc3339 : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-samba : Depends: python (< 2.8) but 3.7.0-1 is to be installed
python-setuptools : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-six : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
python-talloc : Depends: python (< 2.8) but 3.7.0-1 is to be installed
python-tdb : Depends: python (< 2.8) but 3.7.0-1 is to be installed
Depends: python:any (>= 2.7.5-5~)
python-tz : Depends: python (< 2.8) but 3.7.0-1 is to be installed
python-urllib3 : Depends: python:any (< 2.8)
Depends: python:any (>= 2.7.5-5~)
samba : Depends: python (< 2.8) but 3.7.0-1 is to be installed
Recommends: attr but it is not going to be installed
Recommends: samba-dsdb-modules but it is not going to be installed
Recommends: samba-vfs-modules but it is not going to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).
跑步让我害怕，所以我选择不：
$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree
Reading state information... Done
Correcting dependencies... Done
The following packages will be REMOVED:
iotop python-acme python-asn1crypto python-certifi python-cffi-backend python-chardet python-configparser python-crypto python-cryptography python-dnspython python-enum34 python-funcsigs python-future python-idna python-ipaddress
python-josepy python-ldb python-mock python-openssl python-parsedatetime python-pbr python-pkg-resources python-pyicu python-requests python-requests-toolbelt python-rfc3339 python-samba python-setuptools python-six python-talloc
python-tdb python-tz python-urllib3 samba samba-common-bin samba-libs
0 upgraded, 0 newly installed, 36 to remove and 0 not upgraded.
After this operation, 56.7 MB disk space will be freed.
Do you want to continue? [Y/n]
有什么办法可以恢复吗？提前谢谢！
答案1
通常情况下apt-get dist-upgrade，它会通过将软件包替换为您已启用的实际 apt 源中的软件包来解决此问题，但这次在您的系统上它似乎没有这样做。
看起来你需要找到一种需要重新安装原始 Python 包的方法。
幸运的是，您可以通过指定所需的软件包版本来做到这一点。
但首先你必须弄清楚该版本是什么。为此，请使用apt policy。你应该看到类似这样的内容：
error@vmtest-ubuntu1604:~$ sudo apt policy python
python:
Installed: 3.7.0-1
Candidate: 2.7.12-1~16.04
Version table:
*** 2.7.12-1~16.04 500
500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
100 /var/lib/dpkg/status
2.7.11-1 500
500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
现在您知道了它的版本号，您可以具体安装它：
error@vmtest-ubuntu1604:~$ sudo apt install python=2.7.12-1~16.04
-f（即使有提示，也不要在这里使用。）