Wildcard version is comparable to selecting a version depending on
the result of a dice roll. What I mean with this is, that the version
will be selected based on what the specific user already has in their
cargo registry. This means that the same codebase will compile
wonderfully on one machine but will fail with weird errors like:
`the trait 'From<crossterm::event::Event>' is not implemented for 'Input'`
on an other one.
Additionally crates.io does not accept crates with a bare wildcard
version requirement for aforementioned reasons.
Lastly using direct versions requirement allows to use `cargo upgrade`
to automatically update these requirements to their highest possible
value, as determined by SemVer. This works especially well, when adding
new dependencies with `cargo add`, as this also adds a direct version
requirement.
Benedikt Peetz