micromamba is a tiny version of the mamba package manager.
It is a statically linked C++ executable with a separate command line interface.
It does not need a base environment and does not come with a default version of Python.
micromamba supports a subset of all mamba or conda commands and implements a command line interface from scratch.micromamba --help:$ micromamba --help Subcommands: shell Generate shell init scripts create Create new environment install Install packages in active environment update Update packages in active environment repoquery Find and analyze packages in active environment or channels remove Remove packages from active environment list List packages in active environment package Extract a package or bundle files into an archive clean Clean package cache config Configuration of micromamba info Information about micromamba constructor Commands to support using micromamba in constructor env See `mamba/micromamba env --help` activate Activate an environment run Run an executable in an environment ps Show, inspect or kill running processes auth Login or logout of a given host search Find packages in active environment or channels
To activate an environment just call micromamba activate /path/to/env or, when it's a named environment in your :ref:`root prefix<root-prefix>`, then you can also use micromamba activate myenv.
micromamba expects to find the root prefix set by $MAMBA_ROOT_PREFIX environment variable. You can also provide it using CLI option -r,--root-prefix.
Named environments then live in$MAMBA_ROOT_PREFIX/envs/.
For more details, please read about :ref:`configuration<configuration>`.
After :ref:`activation<activation>`, you can run install to add new packages to the environment.
$ micromamba install xtensor -c conda-forge
Using create, you can also create environments:
$ micromamba create -n xtensor_env xtensor xsimd -c conda-forge
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conda-forge/noarch [====================] (00m:01s) Done
conda-forge/linux-64 [====================] (00m:04s) Done
Transaction
Prefix: /home/wolfv/miniconda3/envs/xtensor_env
Updating specs:
- xtensor
- xsimd
Package Version Build Channel Size
────────────────────────────────────────────────────────────────────────
Install:
────────────────────────────────────────────────────────────────────────
_libgcc_mutex 0.1 conda_forge conda-forge/linux-64 Cached
_openmp_mutex 4.5 1_gnu conda-forge/linux-64 Cached
libgcc-ng 9.3.0 h5dbcf3e_17 conda-forge/linux-64 Cached
libgomp 9.3.0 h5dbcf3e_17 conda-forge/linux-64 Cached
libstdcxx-ng 9.3.0 h2ae2ef3_17 conda-forge/linux-64 Cached
xsimd 7.4.9 hc9558a2_0 conda-forge/linux-64 102 KB
xtensor 0.21.9 h0efe328_0 conda-forge/linux-64 183 KB
xtl 0.6.21 h0efe328_0 conda-forge/linux-64 Cached
Summary:
Install: 8 packages
Total download: 285 KB
────────────────────────────────────────────────────────────────────────
Confirm changes: [Y/n] ...
After the installation is finished, the environment can be :ref:`activated<activation>` with:
$ micromamba activate xtensor_env
The create syntax also allows you to use specification or environment files (also called spec files) to easily re-create environments.
The supported syntaxes are:
The txt file contains one spec per line. For example, this could look like:
xtensor numpy 1.19 xsimd >=7.4
To use this file, pass:
$ micromamba create -n from_file -f spec_file.txt -c conda-forge
Note
You can pass multiple text spec files by repeating the -f,--file argument.
More powerful are YAML files like the following, because they already contain a desired environment name and the channels to use:
name: testenv channels: - conda-forge dependencies: - python >=3.6,<3.7 - ipykernel >=5.1 - ipywidgets[build_number=!=0]
They are used the same way as text files:
$ micromamba create -f env.yml
Note
CLI options will keep :ref:`precedence<precedence-resolution>` over target prefix or channels specified in spec files.
Note
You can pass multiple YAML spec files by repeating the -f,--file argument.
Using conda you can generate explicit environment lock files. For this, create an environment, activate it, and execute:
$ conda list --explicit --md5
These environment files look like the following and precisely "pin" the desired package + version + build string. Each package also has a checksum for reproducibility:
# This file may be used to create an environment using: # $ conda create --name <env> --file <this file> # platform: linux-64 @EXPLICIT https://conda.anaconda.org/conda-forge/linux-64/_libgcc_mutex-0.1-conda_forge.tar.bz2#d7c89558ba9fa0495403155b64376d81 https://conda.anaconda.org/conda-forge/linux-64/libstdcxx-ng-9.3.0-h2ae2ef3_17.tar.bz2#342f3c931d0a3a209ab09a522469d20c https://conda.anaconda.org/conda-forge/linux-64/libgomp-9.3.0-h5dbcf3e_17.tar.bz2#8fd587013b9da8b52050268d50c12305 https://conda.anaconda.org/conda-forge/linux-64/_openmp_mutex-4.5-1_gnu.tar.bz2#561e277319a41d4f24f5c05a9ef63c04 https://conda.anaconda.org/conda-forge/linux-64/libgcc-ng-9.3.0-h5dbcf3e_17.tar.bz2#fc9f5adabc4d55cd4b491332adc413e0 https://conda.anaconda.org/conda-forge/linux-64/xtl-0.6.21-h0efe328_0.tar.bz2#9eee90b98fd394db7a049792e67e1659 https://conda.anaconda.org/conda-forge/linux-64/xtensor-0.21.8-hc9558a2_0.tar.bz2#1030174db5c183f3afb4181a0a02873d
To install such a file with micromamba, just pass the -f flag again:
$ micromamba create -n xtensor -f explicit_env.txt
Note
Explicit spec files are single-platform.
Using conda-lock, you can generate lockfiles which, like explicit spec files, pin precisely and include a checksum for each package for reproducibility.
Unlike explicit spec files, these "unified" lock files are multi-platform.
These files are named conda-lock.yml by default, and look like:
# This lock file was generated by conda-lock (https://github.com/conda/conda-lock). DO NOT EDIT!
#
# A "lock file" contains a concrete list of package versions (with checksums) to be installed. Unlike
# e.g. `conda env create`, the resulting environment will not change as new package versions become
# available, unless you explicitly update the lock file.
#
# Install this environment as "YOURENV" with:
# conda-lock install -n YOURENV --file conda-lock.yml
# To update a single package to the latest version compatible with the version constraints in the source:
# conda-lock lock --lockfile conda-lock.yml --update PACKAGE
# To re-solve the entire environment, e.g. after changing a version constraint in the source file:
# conda-lock -f environment.yml --lockfile conda-lock.yml
version: 1
metadata:
content_hash:
osx-64: c2ccd3a86813af18ea19782a2f92b5a82e01c89f64a020ad6dea262aae638e48
linux-64: 06e0621a9712fb0dc0b16270ddb3e0be16982b203fc71ffa07408bf4bb7c22ec
win-64: efee77261626b3877b9d7cf7bf5bef09fd8e5ddfc79349a5f598ea6c8891ee84
channels:
- url: conda-forge
used_env_vars: []
platforms:
- linux-64
- osx-64
- win-64
sources:
- environment.yml
package:
- name: _libgcc_mutex
version: '0.1'
manager: conda
platform: linux-64
dependencies: {}
url: https://conda.anaconda.org/conda-forge/linux-64/_libgcc_mutex-0.1-conda_forge.tar.bz2
hash:
md5: d7c89558ba9fa0495403155b64376d81
sha256: fe51de6107f9edc7aa4f786a70f4a883943bc9d39b3bb7307c04c41410990726
category: main
optional: false
- name: ca-certificates
version: 2023.5.7
manager: conda
platform: linux-64
dependencies: {}
url: https://conda.anaconda.org/conda-forge/linux-64/ca-certificates-2023.5.7-hbcca054_0.conda
hash:
md5: f5c65075fc34438d5b456c7f3f5ab695
sha256: 0cf1bb3d0bfc5519b60af2c360fa4888fb838e1476b1e0f65b9dbc48b45c7345
category: main
optional: false
In order to YAML files to be considered as conda-lock files, their name must ends with -lock.yml or -lock.yaml.
To install such a file with micromamba, just pass the -f flag again:
$ micromamba create -n my-environment -f conda-lock.yml