Features added in dev-dependencies are always active inside a virtual workspace

[Nemo157]

Problem

If a crate has a dependency as both a normal dependency and as a dev-dependency, then the features it activates for the dev-dependency will be active during a normal build iff that crate is a member of a virtual workspace.

Steps

Playground building a local workspace showing the error: https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=36347271fd4c23914346a6df034dc1dd

The Error is expected, it is the panic at the end that should not happen.

Possible Solution(s)

No response

Notes

Found while investigating rust-lang/docs.rs#1783

Version

No response

[Eh2406]

resolver and workspaces interact oddly, see #10745 (comment)

[Nemo157]

Ok, setting workspace.resolver = "2" does fix it; and it looks like #10112 tracks adding a warning that would have instantly diagnosed this.