Feature request: support URLs in license_file in meta.yaml

[jvolkening]

Checklist

• I added a descriptive title
• I searched open requests and couldn't find a duplicate

What is the idea?

Support (remote) URLs in about: license_file, in additional to file paths relative to build environment.

Why is this needed?

Currently, for upstream packages without license full-text included, rather than including separate LICENSE file(s) in the recipe, a perma-URL to the fulltext could be used. Since SPDX identifiers are encouraged already, the canonical SPDX URLs could be used (https://spdx.org/licenses/<SPDX_ID>.txt, e.g. https://spdx.org/licenses/MIT.txt). In addition, it may prove useful for auto-generated recipes as a robust alternative to trying to detect license files in the upstream source.

What should happen?

User can specify remote URL in additional to local license file for about: license_file.

Additional Context

No response

[jvolkening]

Follow-up: I see that there is about: license_url mentioned in the codebase and various places, but not well-documented (e.g. issue #3712). As far as I can tell, this is not used in the same way as license_file, for making sure the license text is included in the conda package.

[jaimergp]

You can download the license as part of the source section, and then refer to that (local) path. You can even check sha hashes to ensure it hasn't changed.

[jvolkening]

Thanks...I have played around with doing that, as well as downloading within build script. I though the above feature might help to keep recipes clean. I see your point about being able to confirm the checksum, though.

Feel free to close this issue. It is more of a "wouldn't that be nice" than an urgent need.