Allowing "-"/"_" renaming on crates.io and treat them the same in Cargo.toml dependencies

[rustonaut]

I recently undusted a old crate of mine and published it to crates.io.
Through I made the mistake to forgot to rename "checked_command" to "checked-command"...
There is currently no good way to "fix" this as it is neither possible to publish it with the correct name ("-" instead of "_") nor can it be renamed. This makes sense to a certain degree, as renaming it would brake
dependencies.

I think it would be good if:

1. cargo+crates.io treat "-" and "_" as the same character in all places, including the dependencies field
2. if 1. is implemented renaming "-" to "_" can be added

This can also be helpful for some old crates published when using "-" wasn't the way to go.
It would also make it slightly nicer for new users as they can place the same name
in the [dependencies] section they use with extern crate.

[sgrif]

If we were to do something like this, it would almost certainly need an RFC as it affects cargo as well as crates.io

[rustonaut]

I think I will open a discussion in the internals forum first ;=)
The reason it ended up here was because I hoped there might some "quick fix",
and changes to crates.io/cargo would be more like a long term solution

[carols10cents]

Link to internals discussion: https://internals.rust-lang.org/t/maybe-pre-rfc-improving---in-cargo-crates-io/5251/11

[carols10cents]

I'm confused, if - and _ are treated the same everywhere (assuming it's possible), then why is renaming needed at all?

[rustonaut]

I was approaching this problem from the angle that I would like to rename a some_crate named crate to some-crate.

I agree that one _ and - are treated the same there is no reason to allow renaming (expect to change what is displayed as crate name in crates.io, but then renaming(-/_ only) would break thinks for people using a older cargo version and wouldn't be worth it).

Also by now the main reason why this features would be nice to have is general usability, especially for new people which might read extern some_crate and wonder why using some_crate in Cargo.toml won't work (and everyone frequently looking up if some crate was now named with _ or - ;=) )

[webmaster128]

Our motivation is the other way round: we have cosmwasm-vm published and want to rename to cosmwasm_vm on order to have the same spelling on crates.io and in the imports.