Renaming Validation and Underscores/Hyphens

[cramertj]

Currently with the "rename-dependency" feature it's possible to have something like futures-01 = { version = "0.1", optional = true, package = "futures" }. However, this will cause a --extern futures-01=... flag to rustc, which results in an unusable crate name of futures-01, rather than the usable futures_01. I think there should either be a warning/error on invalid renamings, possibly with an additional conversion of renamed-names from hyphens to underscores (as is normally done with the package name specified in Cargo.toml).

[ehuss]

I think this is a duplicate of #51795.

[cramertj]

@ehuss Yup, thanks-- closing as dup of rust-lang/rust#51795

[cramertj]

Actually-- that issue is filed against rust-lang/rust-- maybe we should keep this one open, since it's actually an issue against cargo?

[ehuss]

Yea, keeping this open is fine. I can take a look to see how difficult it would be to fix.

[cramertj]

Thanks so much for the quick turnaround!