if a package becomes a lib+bin package mid-edit, ra requires a restart to notice

[lolbinarycat]

rust-analyzer version: rust-analyzer 1.86.0 (05f9846 2025-03-31)

rustc version: rustc 1.86.0 (05f9846f8 2025-03-31)

editor or extension: emacs eglot

relevant settings: eglot-ensure in rust-mode-hook

reproduction steps

1. cargo init --lib
2. open the newly created src/lib.rs in editor
3. open (nonexistent) src/main.rs in editor, add fn main() {}, save file
4. you will still be getting an unlined-file error and all LSP features will not work except highlighting error/warning lines

workaround: restart rust-analyzer (in emacs this can be done with M-x eglot)