bug#64099: Emacs 29 - Eglot hint display issue on macOS

[Daniel Martín]

Milan Jovanovic <milanj@gmail.com> writes:

> Hi all,
>
> There is an issue with how Eglot inlay hints are being printed on the macOS
> (both Intel and apple silicon).
> I've tried on Linux with the same versions and it works fine.
>
> Example of broken inlay hints:
> https://user-images.githubusercontent.com/3064500/245880108-a4f43db5-7ebb-43e6-8031-ebb403ee94b3.png
>
> How to reproduce:
> 1. install Emacs 29 from https://emacsformacosx.com or via brew
> https://github.com/d12frosted/homebrew-emacs-plus
>
> 2. install rustup/rustc/cargo/rust-analyzer - https://rustup.rs
>    # curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
>    `rustup component add rust-analyzer`
>
> 3.  create rust project
>    # cargo new inlay-hints
>
>
> copy this code to inlay-hints/src/main.rs
> ==================================
> use std::error::Error;
>
> struct Foo {}
>
> struct Bar {}
>
> type MyResult = Result<Foo, (Bar, String, Box<dyn Error + Send>)>;
>
> fn get_vec_results() -> Vec<MyResult> {
>     todo!()
> }
>
> fn main() {
>     for result in get_vec_results() {
>         match result {
>             Ok(res) => todo!(),
>             Err(err) => todo!(),
>         }
>     }
> }
>
> ==================================
>
> 4. open Emacs (no .emacs and no .emacs.d)
>    # cd inlay-hints
>    # /Applications/Emacs.app/Contents/MacOS/Emacs -Q src/main.rs -f
> rust-ts-mode -f eglot
>       choose/type 'rust-analyzer' as the server
>
>
> ------------------------------------------------------------------------------
> My Emacs:
>
> system-configuration-options:
> "--with-ns '--enable-locallisppath=/Library/Application
> Support/Emacs/${version}/site-lisp:/Library/Application
> Support/Emacs/site-lisp' --with-modules --with-x-toolkit=no"
>
> ELISP> system-configuration-features
> "ACL GLIB GMP GNUTLS JPEG JSON LIBXML2 MODULES NOTIFY KQUEUE NS PDUMPER PNG
> RSVG THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER ZLIB"
>
>
>
> P.S. I'm seeing the same thing with Emacs 28

I can reproduce the issue with a build from https://emacsformacosx.com,
concretely:

29.0.91 (Build 21G217) of 2023-05-14

But I can't reproduce the issue if I build Emacs from the emacs-29
branch, concretely:

29.0.92 (Build 22A380) of 2023-06-21

It could be a bug related to how https://emacsformacosx.com packages
Emacs, but the fact that it also fails in another Emacs distro
(Emacs-plus), I'd say that this is probably a problem in Eglot that may
have been recently fixed.  Could you try an Emacs build from the tip of
the emacs-29 branch?