In Kate, after getting rust-analyzer up and running, I started working on one of my projects that I know has errors. ... No errors showed up. I could make an obvious syntax error by inserting a semicolon in the middle of something, and that would show up, but it seems that rust-analyzer stopped after checking syntax.
Could anyone help fix this? This is a hurdle preventing me from effectively using this editor.
Your IDE should provide a way to access the logs from the plugin (host) and rust-analyzer (server). If rust-analyzer is failing for some reason, there should be context in there.
More likely, though, is that your rust-analyzer plugin for the Kate IDE simply isn't doing enough (potentially just due to configuration). r-a emits very few semantic errors, instead relying on running cargo check (or whatever command you specify, e.g. cargo clippy, or adding --all-features, etc.) whenever the code changes (typically on save).