Frequently Asked Questions#

What’s the difference between the available solvers in conda?#

Please refer to the section “Technical differences between libmamba and classic” in the libmamba-vs-classic docs.

How do I uninstall it?#

If you don’t want to use the solver anymore, follow these instructions:

Warning

Please make sure you follow all steps below to uninstall the solver!

  1. If you configured it as the default solver, make sure you revert it with:

    $ conda config --remove-key solver
# You might also need this:
$ conda config --remove-key experimental_solver

  2. Then, remove the package from base with:

    $ conda remove -n base conda-libmamba-solver

How do I configure conda to use the solver permanently?#

Use the following command to always use libmamba as your default solver:

$ conda config --set solver libmamba

To undo this change permanently, run:

$ conda config --remove-key solver
# You might also need this:
$ conda config --remove-key experimental_solver

I get an error when I try to use the --solver flag#

If you are seeing this error:

CondaValueError: Key 'solver' is not a known primitive parameter.

It might mean you are using an old version of the conda-libmamba-solver package. You can check which version is installed with conda list -n base conda-libmamba-solver.

Before version 22.12, the CLI flag was --experimental-solver. We recommend you upgrade to conda 22.11 or above, and then conda-libmamba-solver 22.12 or above.

See the 22.12.0 announcement post for more details on how to upgrade.