In #10472, cargo-add was merged with support for an inline version
syntax of `foo@version`. That also served as the change proposal for
extending that syntax to `cargo yank` for convinience and consistency.
The major difference is that `cargo-add` is specifying a version-req
while `cargo-yank` is specifying a version.
This doesn't use the full `pkgid` syntax because that allows syntax that
is unsupported here.
This doesn't use `cargo-add`s parser because that is for version reqs.
In addition to `foo:1.2.3`, we now support `foo@1.2.3` for pkgids. We
are also making it the default way of rendering pkgid's for the user.
With cargo-add in #10472, we've decided to only use `@` in it and to add
it as an alternative to `:` in the rest of cargo. `cargo-add`
originally used `@`. When preparing it for merge, I switched to `:` to
be consistent with pkgids. When discussing this, it was felt `@` has
precedence in too many tools to switch to `:` but that we should instead
switch pkgid's to use `@`, in a backwards compatible way.
See also https://internals.rust-lang.org/t/feedback-on-cargo-add-before-its-merged/16024/26?u=epage
During the design conversations on cargo-add, we noticed that
`cargo-install` has a public flag `--version` and an invisible alias
`--vers` while `cargo-yank` has a public flag `--vers`. This switches
`cargo-yank` to publicly use `--version` and have an invisible alias
`--vers`, making them consistent.
Completions are a best guess.
