How to decide between "host" and "build" requirements?

[JesperBrink]

Right now the methods bioconda_utils_iterative_build and alpine_iterative_build returns a list with dependencies that should be added to the recipe.

The question is then: how do we find out if a requirement is a "build" or a "host" requirement?

[Hogfeldt]

For info about the difference between build and host can be found here: https://docs.conda.io/projects/conda-build/en/latest/resources/define-metadata.html#requirements-section

[Hogfeldt]

To summarize to above mentioned link:

• Build: Tools to build the package with for example gcc, cmake, autoconf etc.
• Host: Packages which should be build for the target by the above tools

[Hogfeldt]

We could eventually add tags to the known packages. The tags could be something like 'build-tool' for packages like gcc or cmake. Libraries like hdf5 could be tagged 'lib'. This way we could check if the package is a library or a build tool, an then determine rather it should or shouldn't be added to host or build.

[Hogfeldt]

I have pushed a quick fix, where we just check a list of known packages before adding a package. We should probably find a more long term solution.