CEP: run_exports in sharded repodata

[baszalmstra]

We propose the store run_exports in sharded repodata shards.

Given that a lot of technical limitations have been mitigated with sharded repodata we propose to also store run_exports in the shards. This allows build tools to acquire run export information more easily and faster.

📝 Rendered

The sharded repodata served by https://prefix.dev already implements this behavior. Rattler-build can also use the run_exports directly from repodata which speeds up resolution during setup as no extra steps are required to determine the run_exports.

[baszalmstra]

I also opened a thread on zulip to discuss this proposal in more detail: https://conda.zulipchat.com/#narrow/channel/457607-general/topic/CEP.3A.20run_exports.20in.20sharded.20repodata if anyone is interested. 😄

[baszalmstra]

Related to #87 and #88

[jakirkham]

Thanks Bas! 🙏

Would this allow us to repodata patch run_exports too? 😉

[baszalmstra]

Would this allow us to repodata patch run_exports too?

Yes! the last paragraph in the CEP is about that.

[beckermr]

We probably need to specify something about tools that don't use the repodata shards should deal with run export patches. Otherwise, we might have different tools seeing different run exports for a patched package.

[baszalmstra]

We probably need to specify something about tools that don't use the repodata shards should deal with run export patches. Otherwise, we might have different tools seeing different run exports for a patched package.

Thats a good point, do you have something in mind?

[beckermr]

Not right now. For channels with a separate run exports JSON blob, that blob can be patched. Channels without this extra file, there is no real way to do this except to have the user download the patches and apply them on the fly. :/

[baszalmstra]

I added some extra text to the CEP to explain how run export patches should be handled. Does that make things clearer @beckermr ?

[beckermr]

I am still confused. The new text covers patching run exports for non-shareded repodata. For sharded repodata, are the run export patches pulled from "run_exports_patch_instructions.json" as well?