Migrate from classic conda-exec#

The conda-forge::conda-exec package name existed before this project. Version 0.2.1 was a 2020 package for executing commands inside a conda environment. Version 0.3.0 and later provide the modern conda-exec tool described in this documentation.

Treat the upgrade as a package replacement, not as a compatible command-line upgrade.

Check what is installed#

Check the environment where conda itself is installed. This is usually base:

conda list -n base conda-exec

If you installed the old package into another environment, check that environment instead:

conda list -n my-env conda-exec

Install the modern package#

Install conda-exec >=0.3.0 into the environment that provides your conda command:

conda install -n base -c conda-forge "conda-exec>=0.3.0"

The version constraint matters. Without it, an environment with old pins or old repodata can keep selecting the historical 0.2.1 package.

Update completion support#

Shell completion is optional, but the new completion metadata needs conda-completion >=0.3.0:

conda install -n base -c conda-forge "conda-completion>=0.3.0"

After updating completion support, reinstall or refresh your shell hooks using the conda-completion documentation for your shell.

Verify the new command#

Check that the conda plugin and standalone alias are available:

conda exec --help
ce --help

Then run a small tool:

conda exec ruff --version

The first run creates a cached environment. Later runs reuse it.

Adjust old usage#

The historical conda-forge package and the modern conda-exec package do not share a command-line contract. Replace old invocations with one of the modern forms:

conda exec ruff check .
conda exec --with pytest ruff check .
conda exec -c bioconda samtools view file.bam
conda exec script.py

Use conda run -n ENV COMMAND ... when you want to run a command inside an existing named environment. Use conda exec COMMAND ... when you want conda-exec to create or reuse an ephemeral cached environment for the requested package.

What happened to the old conda-exec command?#

The historical conda-forge package installed a conda-exec shell command. That command activated an existing environment and then ran another command inside it. It did not install the ce command, register a conda exec plugin subcommand, solve package specs, create cached environments, or read script metadata.

The modern package keeps the conda-exec package name but exposes a different interface:

  • conda exec ... for the conda plugin subcommand

  • ce ... for the standalone console command

It deliberately does not provide a conda-exec ENV COMMAND ... compatibility entry point. That spelling would look compatible while doing something substantially different. For the old “run this command inside an existing environment” use case, use conda’s native command instead:

conda run -n ENV COMMAND ...

For ephemeral tool execution, use:

conda exec TOOL ...
ce TOOL ...

Clean up old assumptions#

  • The modern cache lives under ~/.conda/exec by default.

  • Old cache or configuration from the historical package is not reused.

  • The standalone ce command is equivalent to conda exec.

  • Script execution uses PEP 723 metadata and can be made reproducible with --lock.

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