Conda可以回滚？

Yes。

不得不佩服这帮开发conda的程序员，使用Conda可以回滚（rollback）到上一次的安装状态，而且还非常简单。

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我在某个环境安装某个软件后，我以为没有依赖这个环境的软件，所以一路yes，结果python从2.7上升到了3.6，还有其他几个包被增加和更新。结果我有些软件用不了了！还好一查，Conda提供了回滚的功能特性。

查看conda更新历史

使用conda list --revision

$ conda list --revision
2018-11-19 19:22:48  (rev 0)
    +ca-certificates-2018.03.07 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +certifi-2018.10.15 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +libedit-3.1.20170329 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +libffi-3.2.1 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +libgcc-ng-8.2.0 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +libstdcxx-ng-8.2.0 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +ncurses-6.1 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +openssl-1.1.1 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +pip-18.1 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +python-2.7.15 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +readline-7.0 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +setuptools-40.5.0 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +sqlite-3.25.2 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +tk-8.6.8 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +wheel-0.32.2 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +zlib-1.2.11 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)

2018-11-20 14:51:23  (rev 1)
    +libfuse-3.2.5 (jessetg/label/sbu-hpc)

2018-11-20 14:54:48  (rev 2)
    +java-jdk-8.0.112 (bioconda)
    +openjdk-8.0.112 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/conda-forge)

2018-11-20 15:14:39  (rev 3)
     openjdk  {8.0.112 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/conda-forge) -> 8.0.152 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)}
    -java-jdk-8.0.112 (bioconda)

2019-02-25 10:19:10  (rev 4)
     ca-certificates  {2018.03.07 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main) -> 2019.1.23 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)}
     certifi  {2018.10.15 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main) -> 2018.11.29 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)}
     pip  {18.1 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main) -> 19.0.1 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)}
     python  {2.7.15 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main) -> 3.6.7 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)}
     setuptools  {40.5.0 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main) -> 40.8.0 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)}
     wheel  {0.32.2 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main) -> 0.32.3 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)}
    +asn1crypto-0.24.0 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +cffi-1.11.5 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +chardet-3.0.4 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +cryptography-2.5 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +idna-2.8 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +pycparser-2.19 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +pyega3-3.0.21 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/bioconda)
    +pyopenssl-19.0.0 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +pysocks-1.6.8 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +requests-2.21.0 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +six-1.12.0 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +tqdm-4.31.1 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +urllib3-1.24.1 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)
    +xz-5.2.4 (https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main)

可以看到rev 4就是我今天做的更改。要改回rev 3也很简单。

回滚

使用conda install --version N，N这里是指更改历史的序号。

$ conda install --revision 3

## Package Plan ##

  environment location: /public/home/liuxs/anaconda3/envs/icgc

  added / updated specs: 
    - libfuse
    - pyega3


The following packages will be REMOVED:

    asn1crypto:      0.24.0-py36_0         https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    cffi:            1.11.5-py36he75722e_1 https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    chardet:         3.0.4-py36_1          https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    cryptography:    2.5-py36h1ba5d50_0    https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    idna:            2.8-py36_0            https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    pycparser:       2.19-py36_0           https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    pyega3:          3.0.21-py36_1         https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/bioconda
    pyopenssl:       19.0.0-py36_0         https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    pysocks:         1.6.8-py36_0          https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    requests:        2.21.0-py36_0         https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    six:             1.12.0-py36_0         https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    tqdm:            4.31.1-py_0           https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    urllib3:         1.24.1-py36_0         https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     
    xz:              5.2.4-h14c3975_4      https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main     

The following packages will be DOWNGRADED:

    ca-certificates: 2019.1.23-0           https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main      --> 2018.03.07-0      https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main
    certifi:         2018.11.29-py36_0     https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main      --> 2018.10.15-py27_0 https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main
    pip:             19.0.1-py36_0         https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main      --> 18.1-py27_0       https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main
    python:          3.6.7-h0371630_0      https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main      --> 2.7.15-h9bab390_2 https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main
    setuptools:      40.8.0-py36_0         https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main      --> 40.5.0-py27_0     https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main
    wheel:           0.32.3-py36_0         https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main      --> 0.32.2-py27_0     https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main

Proceed ([y]/n)? y

Preparing transaction: done
Verifying transaction: done
Executing transaction: done

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Conda大法好。

参考：

• http://blog.rtwilson.com/conda-revisions-letting-you-rollback-to-a-previous-version-of-your-environment/