rust-analyzer configuration should also be passed as initializaitonOptions

[lolbinarycat]

eglot-workspace-configuration (what rust-lang/rust uses in its dir-locals.el) only sets the workspace configuration, which is distinct from the initialization options. The recommended way to configure rust-analyzer is via the initialization options, which are currently not being set.

I believe eglot-initialization-options being overridden (without calling cl-call-next-method) by rustic mode also makes this worse by disrupting the normal way of configuring initializationOptions, which is through eglot-server-programs.

[lolbinarycat]

It seems like this was not the root cause of my issue, but it still seems like it would be best to fix somehow. I'm not really sure anymore...

[Erk-]

Can you see what initializaitonOptions get sent through the json first in the eglot debug buffer?

[lolbinarycat]

Not easily for eglot (it would be possible with RA_LOG=info in combination with making rust-analyzer log to a different file with a flag), but lsp-mode shows stderr, and in that case it is quite clear that the configuration getting passed is not the one specified in .dir-locals.el

unsure if lsp-mode has a different variable that should be used for customization.

[lolbinarycat]

ok, managed to get this working with eglot, here's my changes and config

--- old/rustic-lsp.el	2025-06-21 12:10:26.336493182 -0500
+++ new/rustic-lsp.el	2025-06-26 13:57:28.810993748 -0500
@@ -134,7 +134,7 @@
     (if (or (null rustic-enable-detached-file-support)
             (null buffer-file-name)
             (rustic-buffer-crate t))
-        eglot--{}
+        (cl-call-next-method)
       (list :detachedFiles
             (vector (file-local-name (file-truename buffer-file-name))))))

(with-eval-after-load 'eglot
  ;; remove old rustic-mode entry
  (setq eglot-server-programs
		(cl-remove-if (lambda (elm)
  						(and (listp elm)
  							 (listp (car elm))
  							 (eq 'rustic-mode (caar elm)))) eglot-server-programs))
  ;; if a workspace configuration exists, it should also be passed as the initialization options
  ;; unsure if this is 100% needed or if the problem was fully caused by lsp-mode and eglot running simultaniously.
  (add-to-list 'eglot-server-programs
  			   (list
  				(list 'rustic-mode :language-id "rust")
  				eglot-rust-analyzer
  				"rust-analyzer"
				"--verbose"
				"--verbose"
				"--log-file"
				"/tmp/ra.log"
  				:initializationOptions
  				(lambda (_)
  				  (message "ws cfg: %s" eglot-workspace-configuration)
   				  (plist-get eglot-workspace-configuration :rust-analyzer)))))