resolver=2 still needed for workspaces when using rust 2021

[rukai]

This repo demonstrates the problem:
https://github.com/rukai/resolver2-workspace-bug

It includes wgpu 0.11 which requires resolver 2.

• If you include resolver = 2 in the workspace Cargo.toml it builds fine.
• If you remove resolver = 2 from the workspace Cargo.toml it fails with resolver = 1 related errors.

Meta

Occurs on:

• cargo 1.57.0-nightly (7fbbf4e8f 2021-10-19)
• cargo 1.56.0 (4ed5d137b 2021-10-04)

[cuviper]

I guess this is because a virtual manifest doesn't have an edition of its own, but this is a Cargo issue.
(I don't have access to transfer it myself.)

[rukai]

thanks, I can see there is already an issue there rust-lang/cargo#9996
So i'll close this one.

[rukai]

Thinking about this, I think it really is a critical bug, possibly deserving of a 1.56.1 that either fixes the issue or rolls back resolver = 2 default,
So im reopening this as I want to make sure the right people are seeing it.
Feel free to close if thats not needed. :)

[cuviper]

We can consider that (cc @rust-lang/release), but IMO it's not a regression, so it wouldn't deserve a point release.

[ehuss]

Thanks for the report! The resolver is inherently a global setting, and in a workspace can only be set at the workspace level. The edition cannot be set globally (tracked in rust-lang/cargo#5784), so it must be set with the resolver = "2" field. There was some clarification added to the edition guide about workspace behavior, but unfortunately did not make it into the stable docs.

I'm going to close as this is working as intended.