add snowline Laplace approximation and Importance Sampling python package for Bayesian inference

[JohannesBuchner]

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[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/snowline) and found it was in an excellent condition.

[JohannesBuchner]

I am seeing this error:

Reloading output folder: /home/conda/staged-recipes/build_artifacts
Mamba failed to solve:
 - pypmc
 - python 3.9.* *_cpython
 - pytest-runner
 - numpy 1.20.*
 - pip
 - iminuit

with channels:
 - local
 - conda-forge
 - conda-forge

The reported errors are:
- Encountered problems while solving:
-   - package pypmc-1.2-py37hc105733_0 requires python_abi 3.7.* *_cp37m, but none of the providers can be installed

pypmc is a cpython package that snowline depends on.

I don't understand why "python 3.9.* *_cpython" tries to pull in the py37h version of pypmc.

iminuit is another cpython package that snowline depends on. Its recipe is here: https://github.com/conda-forge/iminuit-feedstock/blob/main/recipe/meta.yaml

This stackoverflow question has the same error but from a user perspective.

snowline is pure python, but requires the two cpython packages.

@conda-forge/help-python-c, can you please help?

[JohannesBuchner]

Figure out the tests and fix the incorrect runtime requirements. It's fine if Windows/OSX fails due to missing dependencies.

Tests are fixed by installing openssh to make openmpi work.

Added explanation on the additional requirements (these are for optional features), I will add a extra_require to the setup.py on the next release.

[carterbox]

Tests are fixed by installing openssh to make openmpi work.

Looks like openssh is only required because these packages are being built inside a container? It's not actually a direct dependency of your package. Only direct dependencies of your package go in the requirements section. Packages that are only required for the tests go in the test/requires section, not the requirements/run section.

[JohannesBuchner]

Tests are fixed by installing openssh to make openmpi work.

Looks like openssh is only required because these packages are being built inside a container? It's not actually a direct dependency of your package. Only direct dependencies of your package go in the requirements section. Packages that are only required for the tests go in the test/requires section, not the requirements/run section.

Thank you for pointing this out! I made the change.

[JohannesBuchner]

I think this is ready to be merged