Configuration

Basic options

conda-libmamba-solver is a solver plugin and can be configured with the same settings as the classic solver. This is usually done via the conda config subcommand. Read the conda configuration docs and check for the general solver options there.

Advanced options

Additionally, conda-libmamba-solver can be further configured via special environment variables. We do not recomment using these options in production environments. Their behavior might change in the future, or they can be entirely removed without prior notice.

• CONDA_LIBMAMBA_SOLVER_MAX_ATTEMPTS: Maximum number of attempts to find a solution. By default, this is set to the number of installed packages in the environment. In commands that involve a large number of changes in a large environment, it can take a bit to relax the constraints enough to find a solution. This option can be used to reduce the number of attempts and “give up” earlier.

• CONDA_LIBMAMBA_SOLVER_DEBUG_LIBSOLV: Enable verbose logging from libsolv. Only has an effect if combined with -vvv in the CLI. Note that this will incur a big performance overhead. Only use when debugging solver issues.

Sharded Repodata

Sharded repodata is a feature that enables faster repodata fetching and is enabled by default. Since conda 26.5, fetching sharded repodata is handled by conda itself and controlled by its repodata_use_shards setting. If you need to disable it and only use classic repodata fetching, run the following conda config command:

conda config --set repodata_use_shards false

Alternatively, you can disable it via an environment variable:

export CONDA_REPODATA_USE_SHARDS=false

To disable it for a single command only, pass the --no-repodata-use-shards flag.