Build locally#

Local development environment#

Clone the repo#

Start by cloning the repo:

git clone https://github.com/mamba-org/mamba.git

Then move to the newly created directory:

cd mamba

Install dev requirements#

Make sure you have Mamba’s development requirements installed in your environment.
To do so, you can use your existing mamba or micromamba installation:
mamba env update --name <env_name> --file ./<project>/environment-dev.yml

micromamba install --name <env_name> --file ./<project>/environment-dev.yml

Pick the correct environment spec file depending on the project you want to build.

If you don’t have an existing env, refer to the installation page.

The different parts of this repository are sub-projects, all relying (totally or partially) on cmake configuration.

Note

All cmake commands listed below use bash multi-line syntax. On Windows, replace \ trailing character with ^.

Note

Feel free to use your favorite generator: make, ninja, etc.

Build libmamba#

libmamba build is enabled using BUILD_LIBMAMBA cmake option.

Shared library#

BUILD_SHARED option needs to be activated:

cmake -B build/ \
    -DBUILD_LIBMAMBA=ON \
    -DBUILD_SHARED=ON
cmake --build build/

Note

libmamba cmake target represents the shared library

Static library#

BUILD_STATIC option needs to be activated:

cmake -B build/ \
    -DBUILD_LIBMAMBA=ON \
    -DBUILD_STATIC=ON
cmake --build build/

Note

libmamba-static cmake target represents the static library with static dependencies linkage

Note

The libmamba static library does not embed the dependencies but the cmake target will expose those dependencies to any executable linking on it

Note

The libmamba static lib still has few symbols required from system shared libraries (glibc for instance)

Warning

This version of the library has a small difference versus the shared one, on the way the SSL backend of cURL is set See libmamba/src/core/fetch.cpp for more information

Tests#

C++ tests require libmamba to be built.
To compile the gtest-based C++ test suite, run:
cmake -B build/ \
    -DBUILD_LIBMAMBA=ON \
    -DBUILD_SHARED=ON \
    -DBUILD_LIBMAMBA_TESTS=ON
cmake --build build/

You should now be able to run:

./build/libmamba/tests/test_libmamba

Alternatively you can use:

cmake --build build/ --target test

Note

If you want to run specific or a subset of tests, you can use GTEST_FILTER environment variable or the --gtest_filter flag.

Build libmambapy#

The Python bindings of libmamba, libmambapy can be built by using the BUILD_LIBMAMBAPY cmake option.

You can either rely on libmamba package already installed in your environment and run:

cmake -B build/ \
    -DBUILD_LIBMAMBAPY=ON
cmake --build build/

or rebuild libmamba at the same time:

cmake -B build/ \
    -DBUILD_LIBMAMBA=ON \
    -DBUILD_SHARED=ON \
    -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX \
    -DCMAKE_PREFIX_PATH=$CONDA_PREFIX \
    -DBUILD_LIBMAMBAPY=ON
cmake --build build/

Note

When rebuilding libmamba, you also need to install the library in a path it will be found. Use for that the CMAKE_INSTALL_PREFIX cmake option to point your current development environment, and CMAKE_PREFIX_PATH cmake option to specify the installation prefixes to be searched:

  • -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX [unix]

  • -DCMAKE_PREFIX_PATH=$CONDA_PREFIX [unix]

  • -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX\\Library [win]

  • -DCMAKE_PREFIX_PATH=$CONDA_PREFIX\\Library [win]

You’ll need to install the target to have the bindings Python sub-module correctly located, then you can use pip to install that Python package:

make install -C build/
pip install -e libmambapy/ --no-deps

Note

The editable mode -e provided by pip allows to use the source directory as the Python package instead of copying sources inside the environment You can then change the code without having to reinstall the package

Note

The --no-deps tells pip to skip the dependencies installation, since they are already installed (libmamba installed using cmake)

Note

libmambapy is dynamically linking against libmamba (shared) library

Build mamba#

You need to build and install libmambapy, which is a dependency of mamba, then install mamba:

pip install -e ./mamba/ --no-deps

Note

Other dependencies are already installed from the environment-dev.yml file

Build micromamba#

Dynamically linked#

To build micromamba, activate the BUILD_MICROMAMBA flag in cmake command:

cmake -B build/ \
    -DBUILD_MICROMAMBA=ON \
    -DBUILD_SHARED=ON
cmake --build build/

or rebuild libmamba at the same time:

cmake -B build/ \
    -DBUILD_LIBMAMBA=ON \
    -DBUILD_SHARED=ON \
    -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX \
    -DCMAKE_PREFIX_PATH=$CONDA_PREFIX \
    -DBUILD_MICROMAMBA=ON
cmake --build build/

Note

If you need to install, use the CMAKE_INSTALL_PREFIX cmake option to point your current development environment:

  • -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX [unix]

  • -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX\\Library [win]

You may need to use the CMAKE_PREFIX_PATH cmake option as well, to specify the installation prefixes to be searched:

  • -DCMAKE_PREFIX_PATH=$CONDA_PREFIX [unix]

  • -DCMAKE_PREFIX_PATH=$CONDA_PREFIX\\Library [win]

Note

micromamba will be dynamically linked against libmamba and all its dependencies (libsolv, libarchive, etc.)

Note

MICROMAMBA_LINKAGE default value is DYNAMIC

Statically linked#

You can also build micromamba as a fully statically linked executable. For that, you need to install extra requirements:

micromamba install --name <env_name> --file ./libmamba/environment-static-dev.yml

It will install the development version of dependencies, including static libraries.

Now you can run cmake:

cmake -B build/ \
    -DBUILD_MICROMAMBA=ON \
    -DBUILD_STATIC=ON
cmake --build build/

or with libmamba:

cmake -B build/ \
    -DBUILD_LIBMAMBA=ON \
    -DBUILD_STATIC=ON \
    -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX \
    -DCMAKE_PREFIX_PATH=$CONDA_PREFIX \
    -DBUILD_MICROMAMBA=ON
cmake --build build/

Note

If you decide to build both the static and shared libraries, micromamba will link with the shared one. To link with the static library, pass the additional build option -DMICROMAMBA_LINKAGE=STATIC

Tests#

In order to run the Python-based test suite, you need to set the following environment variables:

export TEST_MAMBA_EXE=build/micromamba/micromamba
export MAMBA_ROOT_PREFIX=YOUR_MICROMAMBA_ROOT_PREFIX

Then, you should be able to run the tests:

pytest micromamba/tests/

Since running all the tests would take a great amount of time, you could choose to run only a specific test. To launch test_env for example, you can run:

pytest micromamba/tests/test_env.py

Note

You could also use pytest -k option to filter by test full name or substring.