Give better error message when the rust-analyzer binar path was set in the user's config but the binary is invalid

Author: rylev

editors/code/src/main.ts

@@ -252,7 +252,12 @@ async function bootstrapServer(config: Config, state: PersistentState): Promise<
     log.info("Using server binary at", path);
 
     if (!isValidExecutable(path)) {
-        throw new Error(`Failed to execute ${path} --version`);
+        if (config.serverPath) {
+            throw new Error(`Failed to execute ${path} --version. \`config.server.path\` or \`config.serverPath\` has been set explicitly.\
+            Consider removing this config or making a valid server binary available at that path.`);
+        } else {
+            throw new Error(`Failed to execute ${path} --version`);
+        }
     }
 
     return path;