PackageNotInstalledError: Package is not installed in prefix

问题

conda update conda >> successful

conda update anaconda >> gives me error saying package is not installed in prefix.

I have single installation of Python distribution on my system. How do I solve this issue?

(base) C:\Users\asukumari>conda info

 active environment : base
active env location : C:\Users\asukumari\AppData\Local\Continuum\anaconda3
        shell level : 1
   user config file : C:\Users\asukumari\.condarc  populated config files : C:\Users\asukumari\.condarc
      conda version : 4.5.9
conda-build version : 3.4.1
     python version : 3.6.4.final.0
   base environment : C:\Users\asukumari\AppData\Local\Continuum\anaconda3  (writable)
       channel URLs : https://repo.anaconda.com/pkgs/main/win-64
                      https://repo.anaconda.com/pkgs/main/noarch
                      https://repo.anaconda.com/pkgs/free/win-64
                      https://repo.anaconda.com/pkgs/free/noarch
                      https://repo.anaconda.com/pkgs/r/win-64
                      https://repo.anaconda.com/pkgs/r/noarch
                      https://repo.anaconda.com/pkgs/pro/win-64
                      https://repo.anaconda.com/pkgs/pro/noarch
                      https://repo.anaconda.com/pkgs/msys2/win-64
                      https://repo.anaconda.com/pkgs/msys2/noarch
      package cache : C:\Users\asukumari\AppData\Local\Continuum\anaconda3\pkgs
                      C:\Users\asukumari\AppData\Local\conda\conda\pkgs
   envs directories : C:\Users\asukumari\AppData\Local\Continuum\anaconda3\envs
                      C:\Users\asukumari\AppData\Local\conda\conda\envs
                      C:\Users\asukumari\.conda\envs
           platform : win-64
         user-agent : conda/4.5.9 requests/2.18.4 CPython/3.6.4 Windows/10 Windows/10.0.16299
      administrator : False
         netrc file : None
       offline mode : False

回答1:

Usually this error, "PackageNotInstalledError: Package is not installed in prefix." is because your custom environment doesn't have the conda infrastructure. Instead, it is in your base only. To update the base environment:

conda update --name base conda

To see what version you have installed:

conda list --name base conda

example output of list;

# packages in environment at /Users/me/miniconda2:
#
# Name                    Version                   Build  Channel
conda                     4.6.14                   py27_0  
conda-env                 2.6.0                h36134e3_0  

回答2:

to solve the problem after message "PackageNotInstalledError: Package is not installed in prefix" package name: anaconda:

    conda update --all
    ...
    Proceed ([y]/n)? y

regards !

回答3:

Just encountered this error. The solution was to run,

conda install anaconda

回答4:

I was getting the following error when trying to update boto3 in my conda environment:

PackageNotInstalledError: Package is not installed in prefix. prefix: /usr/local/anaconda3/envs/myfoldername

package name: boto3

This was after having already just done: conda install anaconda, conda update -n root conda and conda update --all

However, I did finally succeed in updating boto3, by specifying the version number as follows:

conda install boto3=1.12

回答5:

I got this error when I tried to update while my conda environment was activated. The solution was to first deactivate:

conda deactivate

before trying to update:

conda update conda

conda update anaconda

回答6:

I met the same problem in my window1 10. pls change the env to base, because the package "conda" only can be updated in base. regards!

回答7:

This works for me:

source active <your python env>

来源：https://stackoverflow.com/questions/51712693/packagenotinstallederror-package-is-not-installed-in-prefix