I'm not familiar with rust+semver problems.
Can someone please explain what the issue is?
Can someone please explain what the issue is?
In practice a crate's public interface is effectively scattered throughout a number of modules. There's no separate textual interface definition that you could diff to see what you changed without also seeing changes to the implementation. Clients importing your library compile against the whole source.
So in practice if you want to check whether you changed your public interface unintentionally, your best bet is to compare the old and new output of Rust's automated documentation system, which by default is describing only the public interface.
Cargo-semver-checks attempts to automate that.
For Rust folks, I'm talking about auto traits like Send and Sync.
More info and examples here:
https://predr.ag/blog/toward-fearless-cargo-update/
TL;DR: Semver is particularly tricky in Rust and can be broken in many far-from-obvious ways. When a library breaks semver it can cause compile errors in every downstream bit of code that uses it. This sucks for everyone on all sides.
So semver is something that Rust always uses and enforces as opposed to stuff I've seen where it's a manual number added by a human. Cool, I can definitely see how that would cause issues, and your examples+blog were helpful. Much appreciated!
Could there be a workflow in Rust compilation or packaging that uses your tool and says "oops, looks like the semver needs to be updated, can I do that for you?"
Running `cargo publish` would check for semver issues and alert if it finds anything. Users would be able to override it, of course, but most often they'd probably accept the version change or revert the semver break if it wasn't intended.