Tagging @ViktorHofer as an area owner

Why not just add a P2P here as a Target BeforeTargets="Build"? https://github.com/dotnet/runtime/blob/master/src/libraries/src.proj#L21

Do we know the exact places where we need CoreLib? I assume we want a P2P in runtime.depproj (or its callers) as well?

cc @safern @ericstj for opinions.

Do we know the exact places where we need CoreLib? I assume we want a P2P in runtime.depproj (or its callers) as well?

Corelib is special and doesn't go through the config system, do we want to do that? I rather use the subset feature to keep the change simple and minify risk of breaking people.

Corelib is special and doesn't go through the config system, do we want to do that?

The config system shouldn't matter here as a) it isn't imported for System.Private.CoreLib and b) it doesn't do anything when a project doesn't multi-target.

The config system shouldn't matter here as a) it isn't imported for System.Private.CoreLib and b) it doesn't do anything when a project doesn't multi-target.

That's true.

Also, how would P2P work with different configurations? Runtime is usually built with different configurations, I know this is managed and just for building and not what we use to run tests or ship, but this could confuse people.

@ericstj or @Anipik can answer to that

so the job is mostly green with current changes (except for special casing for webassembly). So based on what the recommendation is on how to build corelib we can proceed with this.

so the job is mostly green with current changes (except for special casing for webassembly)

I believe the wasm case is special because we don't have support to build System.Private.CoreLib for wasm (it might just work) and we were using the Linux_x64 corelib.

this change is ready to merge. Havent seen an update on the discussion above, but that can be done as a separate change if required. @safern @ViktorHofer please review.