How can you "clone" a conda environment into the base (root) environment?

Question

I'd like the base (root) environment of conda to copy all of the packages in another environment. How can this be done?

Answer 1

There are options to copy dependency names/urls/versions to files.

Recommendation

Normally it is safer to work from a new environment rather than changing root. However, consider backing up your existing environments before attempting changes. Verify the desired outcome by testing these commands in a demo environment. To backup your root env for example:

λ conda activate root
λ conda env export > environment_root.yml
λ conda list --explicit > spec_file_root.txt

Options

Option 1 - YAML file

Within the second environment (e.g. myenv), export names⁺ to a yaml file:

λ activate myenv
λ conda env export > environment.yml  

then update the first environment⁺ (e.g. root) with the yaml file:

λ conda env update --name root --file environment.yml

Option 2 - Cloning an environment

Use the --clone flag to clone environments (see @DevC's answer):

λ conda create --name myclone --clone root

This basically creates a direct copy of an environment.

Option 3 - Spec file

Make a spec-file⁺⁺ to append dependencies from an env (see @Ormetrom):

λ activate myenv
λ conda list --explicit > spec_file.txt
λ conda install --name root --file spec_file.txt

Alternatively, replicate a new environment (recommended):

λ conda create --name myenv2 --file spec_file.txt

See Also

• conda env for more details on the env sub-commands.
• Anaconada Navigator desktop program for a more graphical experience.
• Docs on updated commands. With older conda versions use activate (Windows) and source activate (Linux/Mac OS). Newer versions of conda can use conda activate (this may require some setup with your shell configuration via conda init).
• Discussion on keeping conda env

Extras

There appears to be an undocumented conda run option to help execute commands in specific environments.

# New command
λ conda run --name myenv conda list --explicit > spec_file.txt

The latter command is effective at running commands in environments without the activation/deactivation steps. See the equivalent command below:

# Equivalent
λ activate myenv
λ conda list --explicit > spec_file.txt
λ deactivate

Note, this is likely an experimental feature, so this may not be appropriate in production until official adoption into the public API.

^{+ Conda docs have changed since the original post; links updated.}

^{++ Spec-files only work with environments created on the same OS. Unlike the first two options, spec-files only capture links to conda dependencies; pip dependencies are not included.}