Environment variables#

Environment variables that conda-exec reads, sets, or respects during operation.

conda-exec variables#

CONDA_EXEC_HOME

Override the base data directory for cached environments. Default: ~/.conda/exec/. The value is expanded with ~ support and resolved to an absolute path. When set, all cached environments are stored under $CONDA_EXEC_HOME/envs/ instead of ~/.conda/exec/envs/. Useful for testing or placing the cache on a different filesystem.

export CONDA_EXEC_HOME=/scratch/conda-exec
conda exec ruff check .
# Environment stored at /scratch/conda-exec/envs/ruff--<hash>/
CONDA_EXEC_AUTO_CLEAN

Enable or disable automatic cache cleanup after successful tool runs. Default: true. Accepted truthy values are 1, true, yes, and on; accepted falsy values are 0, false, no, and off.

export CONDA_EXEC_AUTO_CLEAN=false
CONDA_EXEC_CLEAN_INTERVAL

Number of successful conda exec TOOL runs between automatic cleanup checks. Default: 50. Values must be positive integers.

export CONDA_EXEC_CLEAN_INTERVAL=25
CONDA_EXEC_CLEAN_AGE

Remove cached environments that have not been used in this many days when automatic cleanup runs. Default: 30. Values must be zero or greater.

export CONDA_EXEC_CLEAN_AGE=14

conda plugin settings#

Automatic cleanup can also be configured persistently through conda’s plugin configuration in .condarc:

plugins:
  conda_exec_auto_clean: true
  conda_exec_clean_interval: 50
  conda_exec_clean_age: 30

The direct CONDA_EXEC_* variables above override these plugin settings. conda’s standard plugin environment variable form is also supported, for example CONDA_PLUGINS_CONDA_EXEC_AUTO_CLEAN=false.

Variables set during tool execution#

PATH

Modified before the tool process starts. The behavior depends on the --activate flag:

  • Without --activate (default): the prefix’s bin/ directory (or Scripts/ on Windows) is prepended to PATH. No other environment variables are changed.

  • With --activate: conda’s activator computes the subprocess environment, which modifies PATH and may set or unset additional variables (see CONDA_PREFIX below).

CONDA_PREFIX

Only set when --activate is used. Points to the ephemeral environment prefix (e.g. ~/.conda/exec/envs/samtools--7e2d9f04/). Without --activate, this variable is not set.

Standard conda variables#

conda-exec runs within conda’s plugin framework and inherits conda’s context system. The following standard conda environment variables are respected through conda.base.context.context:

CONDA_ALWAYS_YES

When set to true, skip confirmation prompts (equivalent to --yes on the command line). Applies to conda exec --clean.

CONDA_DRY_RUN

When set to true, report what would be done without making changes. Applies to conda exec --clean.

CONDA_SUBDIR

Override the platform subdirectory used for package resolution (e.g. linux-64, osx-arm64). Passed through to the solver.

Note

Use conda exec --list --json for conda-exec’s machine-readable cache listing. The list command is not currently controlled by conda’s global CONDA_JSON setting.

Path resolution order#

The base data directory is resolved in this order:

  1. CONDA_EXEC_HOME environment variable, if set

  2. ~/.conda/exec/ (primary location on all platforms)

  3. On Windows only, if ~/.conda/exec/ does not exist: platformdirs.user_data_dir("conda", "conda") / "exec" as a fallback matching conda’s own data directory conventions

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