bump dependencies

[CJ-Wright]

@CJ-Wright commented on Wed Feb 28 2018

It would be good to have a way to bump dependencies along with the versions.
See: https://github.com/conda/conda-build/blob/master/conda_build/skeletons/pypi.py#L869
@isuruf
@sodre

[jakirkham]

An easier strategy to consider, since we only want to parse the requirements, might be to run python setup.py egg_info in the source directory. This will generate some metadata in a *.egg-info directory (where * is the project name). One of the things it generates in this directory is requires.txt. This lists all of the requirements of the package including extra requirements in a standard requirements.txt file, which could be loaded and parsed with something like requirements-parser ( seems we don't have that yet conda-forge/staged-recipes#5303 ;).

Also might look at pipreqs for some useful thoughts. Though it looks like it mainly scans for imports. Still could be handy for detecting a setuptools requirement at run time (e.g. uses pkg_resources), which is something people seldom state explicitly. Though maybe it is easier to just find that one piece through "grepping".

[CJ-Wright]

How do we decide between run and build requirements?

[jakirkham]

They are run dependencies. It doesn't export build dependencies (e.g. setup_requires). Just checked.

More generally we have discouraged anyone from adding stuff to build beyond python and setuptools/pip unless it is actually used for the build (e.g. cython). There are historic reasons for it, but it is also just cleaner and a bit nicer on the CIs. It will also make this task easier if we stick to that guideline.

IOW if someone actually has a build dependency, it is reasonable to assume that they are linking to it or maybe it's some other build tool. Alternatively it could be an old recipe not following best practices.

IMHO it is fair to say we don't touch build dependencies. It's also probably best as the maintainer may have pinned the build requirements due to to build issues that would not be obvious from inspecting the source (e.g. breaks on some version of cython).

Sound reasonable? Other thoughts/concerns?

[CJ-Wright]

That sounds reasonable to me. I have seen a few PRs with massive build requirements (as python packages) but those usually end up being not needed.

I usually default to the "bot make reasonable decision which is non-aggressive and maintainers/reviewers can be more aggressive", so having the bot default to the recipe for build requirements goes well with that sentiment.

[jakirkham]

Sure. Along those lines it would be reasonable to parse out optional dependencies that maintainers already harden and refresh those dependencies. Am hopeful this ends up being mostly straightforward.

[jakirkham]

Would it be possible to add a note to the PRs reminding maintainers to check dependencies themselves? After talking to a few maintainers, I don't think they are aware the bot isn't doing this for them.

[jakirkham]

Linking issue ( pypi/warehouse#474 ) as this would provide an API for querying dependencies from Warehouse.

[jdblischak]

@jakirkham @CJ-Wright Here are some thoughts about handling dependencies for R packages.

conda skeleton cran does a good job of determining the R package dependencies. Since the bot script already depends on conda-smithy, using conda-build does not add an extra dependency. One possible strategy would be:

1. Download the current meta.yaml from the feedstock repo. Extract current dependencies using conda_build.metadata.MetaData. Only keep non-R dependencies, i.e. those that do not start with r-.
2. Run conda skeleton cran (or conda_build.api.skeletonize). Extract the updated dependencies.
3. Merge the R and non-R dependecies
4. Insert the merged dependencies back into the original meta.yaml (along with the updated version number and sha256)

If you're interested in obtaining the dependencies of many packages (e.g. to build a dependency graph), one option would be to call available.packages() via rpy2.

Hopefully some of that was useful. Please let me know if you have specific questions.