Steps to reproduce

Install gopls language server using go install golang.org/x/tools/gopls@latest
Make language server available in PATH by running export PATH="${GOPATH:-$HOME/go}/bin:$PATH"
Save this code in ~/mre.el
```
(cd "~")
```

;; download dependencies to file-system (shell-command "git clone --depth=1 https://github.com/joaotavora/eglot") (shell-command "git clone --depth=1 https://github.com/dominikh/go-mode.el go-mode")

;; add packages to load-path (add-to-list 'load-path "~/eglot") (add-to-list 'load-path "~/go-mode")

(require 'go-mode) (require 'eglot) (add-hook 'go-mode-hook #'eglot-ensure) (setq flymake-no-changes-timeout nil)

(make-directory "~/repr" t) (find-file "~/repr/test.go") (insert " package main import \"fmt\" func main() { fmt.Println(\"test\") }") (save-buffer)

- Run `emacs -Q -l ~/mre.el`
- Add or remove comment from `fmt.Println` statement and save buffer - flymake diagnostic will be outdated and contain diagnostic from previous save.

Contents of `M-x eglot-events-buffer`: https://gist.github.com/ipvych/391ac3103e168b9d0ae75f8322191fa9
# System information
- `(emacs-build-description)`:

In GNU Emacs 29.1 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo version 1.16.0, Xaw3d scroll bars) Windowing system distributor 'The X.Org Foundation', version 11.0.12101008 System Description: NixOS 23.11 (Tapir)

Configured using: 'configure --prefix=/nix/store/956mdihpqbh2x1bm75xw80zjksgsbpgn-emacs-29.1 --disable-build-details --with-modules --with-x-toolkit=lucid --with-xft --with-cairo --with-native-compilation --with-tree-sitter --with-xinput2'

- `gopls version`:

golang.org/x/tools/gopls v0.13.2 golang.org/x/tools/gopls@v0.13.2 h1:Pyvx6MKvatbX3zzZmdGiFRfQZl0ohPlt2sFxO/5j6Ro=

ACK. There's not much to do here, except recommending you don't do this customization for Eglot.

When the buffer is saved, Flymake asks for diagnostics, and at that time, the server hasn't yet published the notification that says there are no diagnostics at all. According to the LSP spec, it can take all the time in the world for that.

There is now a "pull diagnostics" specification in LSP that would presumably fix this, but Eglot does not yet support this feature.

Maybe this 100% untested hack will work for you:

(cl-defmethod eglot-handle-notification :after
  (_server (_method (eql textDocument/publishDiagnostics)) &key uri
           &allow-other-keys)
  (when-let ((buffer (find-buffer-visiting (eglot-uri-to-path uri))))
    (with-current-buffer buffer
      (if (and (eq nil flymake-no-changes-timeout)
               (not (buffer-modified-p)))
          (flymake-start t)))))

joaotavora / eglot

gopls reporting is delayed when `flymake-no-changes-timeout` is set to nil #1296

Steps to reproduce