User Guide

The conda-libmamba-solver plugin allows you to use libmamba, the same libsolv-powered solver used by mamba and micromamba, directly in conda.

How to install

If you have a recent conda (23.10 or later), you don’t have to do anything. conda-libmamba-solver is already preconfigured as default. For older versions conda, we simply recommend updating conda to a more recent version:

$ conda update -n base conda

If this command fails, check this entry in the FAQ section: I have an older conda and I can’t install conda-libmamba-solver.

Update from the experimental versions

Please refer to the v22.12.0 release notes for more details on how to update from a previous version if you were already using the experimental builds (conda-libmamba-solver 22.9 and below).

Usage

From conda 23.10, conda-libmamba-solver is the default solver. You don’t have to do anything else. It will just work.

Usage with conda 23.9 and below

conda <23.10 won’t use conda-libmamba-solver by default. It will still rely on the classic solver.

Sporadic use

To enable it for one operation, you can use the --solver flag, available for conda create|install|remove|update commands.

$ conda install tensorflow --solver=libmamba

Note: The --solver flag is also exposed as an environment variable, CONDA_SOLVER, in case you need that.

Set as default

To enable it permanently, you can add solver: libmamba to your .condarc file, either manually, or with this command:

$ conda config --set solver libmamba

Revert to classic

If you ever need to use the classic solver temporarily, use --solver flag:

$ conda install numpy --solver=classic

Finally, if you need to revert the default configuration back to classic, you can:

• Run conda config --set solver classic (to make your choice explicit).

Tip

If you are unsure what configuration is being used by conda, you can inspect it with conda config --show-sources.