Advanced Setup Considerations

This page is for contributors and developers installing MsPASS from a source checkout. Most users should use the Docker quick start or the Conda installation guide.

Source builds

MsPASS is not a Python-only package. Installing it invokes CMake to compile the mspasspy.ccore C++ extension. Follow the project’s source-build instructions for the required compilers and libraries. The current package metadata requires Python 3.10 or newer.

Use an isolated environment

Create and activate a Conda environment or Python virtual environment before building. An isolated environment avoids conflicts with the operating system’s Python packages and with other MsPASS checkouts.

After activation, confirm that Python and pip refer to the intended environment:

python -c "import sys; print(sys.executable)"
python -m pip --version

Install from the root of the source tree with the command specified by the source-build procedure. When that procedure has already installed all dependencies, the local installation command is:

python -m pip install --no-deps -v .

Using python -m pip ensures that pip installs for the active interpreter. Do not add --user inside a Conda or virtual environment: it can install a second copy outside the environment. Also avoid sudo pip, which can modify files managed by the operating system.

Check which copy is imported

If multiple installations may exist, check both the selected interpreter and the imported package:

python -c "import sys, mspasspy; print(sys.executable); print(mspasspy.__file__)"
python -m pip show mspasspy

The interpreter, imported package, and location reported by pip should all refer to the intended environment or checkout. PATH chooses the Python executable, but it does not by itself control Python’s package search path.

If an old installation is imported, first identify its location with the commands above. Remove it with the interpreter that owns that installation; do not delete arbitrary files from site-packages. Old PYTHONPATH entries can also shadow a new build, so start a clean shell and unset that variable when diagnosing an unexpected import:

unset PYTHONPATH

Activate the intended environment again, rebuild, and repeat the location check before running tests.