fwiw if you do a cargo build you should be able to see the error messages in the correct context. If I replicate line 25 in a little test project and run cargo build I get

error: expected one of `.`, `;`, `?`, `else`, or an operator, found `{`
 --> src/main.rs:4:43
  |
4 |     let guess: u32 = guess.trim().parse() {
  |                                           ^ expected one of `.`, `;`, `?`, `else`, or an operator

error: could not compile `unacceptable-rs` (bin "unacceptable-rs") due to 1 previous error

If I try this with a blank helix config I don't get any of the text output from rust-analyzer at all, just the three dots indicating there's a problem there, so it's unlikely it's a bad design choice on helix's part.