ok

config/emacs/emacs.org

@@ -1042,6 +1042,23 @@ this should be useful later
                     :cargo (:features ["all"]))))
 
     (add-hook 'rustic-mode-hook #'setup-rust)
+    (add-hook 'rust-mode-hook #'setup-rust)
+
+
+    ;; expects initializationOptions done a bit differently (see below).
+    (defclass eglot-rust-analyzer (eglot-lsp-server) ()
+      :documentation "A custom class for rust-analyzer.")
+
+    ;; Rust-analyzer requires the workspaceConfiguration sent as
+    ;; initializationOptions at startup time. See
+    ;; https://github.com/joaotavora/eglot/discussions/845 and
+    ;; rust-analyzer’s manual page.
+    (cl-defmethod eglot-initialization-options ((server eglot-rust-analyzer))
+      eglot-workspace-configuration)
+
+    ;; Use our custom ‘eglot-rust-analyzer’ for ‘rust-mode’.
+    (add-to-list 'eglot-server-programs
+                 '(rustic-mode . (eglot-rust-analyzer "rust-analyzer")))
     
     :custom
     (rustic-cargo-use-last-stored-arguments t))