Support depending on crates with any case of the original name

[carols10cents]

Similarly to #2775, because we consider a crate name to be unique no matter what the casing of the name, we should look up crates in the index regardless of whether the casing in a Cargo.toml matches the casing in the index exactly.

The directory and file names in the index are already all lowercase.

[alexcrichton]

I think this may already happen?

[carols10cents]

If I make a Cargo.toml with:

[dependencies]
LIBC = "*"

and then cargo build, I get:

error: no matching package named `LIBC` found

[alexcrichton]

Ah ok, that's a different issue then what's in the title!

[carols10cents]

o.O how so? when depending on a crate, doesn't that look up the crate in the index?

[alexcrichton]

Crate name comparison happens a few places in Cargo. Cargo already case-insensitively looks up the crate in the registry, but the name is later rejected due to the wrong case. It's elsewhere in Cargo's crate graph resolver that the case mapping would need to happen I believe.

[jasonwilliams]

@alexcrichton @carols10cents hey
Is there any update to this? I have a crate in Cargo which has a capital letter and i would like to change it

[vcfxb]

I am also waiting on an update to this

[epage]

I feel like having something besides the canonical name in Cargo.toml will make it harder for users and tooling to process Cargo.toml files. I'm going to propose to the cargo team that we close this.