Auto merge of #16416 - Young-Flash:cargo_ext_detect, r=lnicola

internal: VS Code: report conflict with `panicbit.cargo`

<img width="359" alt="notification" src="https://github.com/rust-lang/rust-analyzer/assets/71162630/420b9f34-ba73-4436-b868-6cd87c62287d">

related to #16392

editors/code/src/main.ts

@@ -25,16 +25,7 @@ export async function deactivate() {
 export async function activate(
     context: vscode.ExtensionContext,
 ): Promise<RustAnalyzerExtensionApi> {
-    if (vscode.extensions.getExtension("rust-lang.rust")) {
-        vscode.window
-            .showWarningMessage(
-                `You have both the rust-analyzer (rust-lang.rust-analyzer) and Rust (rust-lang.rust) ` +
-                    "plugins enabled. These are known to conflict and cause various functions of " +
-                    "both plugins to not work correctly. You should disable one of them.",
-                "Got it",
-            )
-            .then(() => {}, console.error);
-    }
+    checkConflictingExtensions();
 
     const ctx = new Ctx(context, createCommands(), fetchWorkspace());
     // VS Code doesn't show a notification when an extension fails to activate
@@ -200,3 +191,26 @@ function createCommands(): Record<string, CommandFactory> {
         revealDependency: { enabled: commands.revealDependency },
     };
 }
+
+function checkConflictingExtensions() {
+    if (vscode.extensions.getExtension("rust-lang.rust")) {
+        vscode.window
+            .showWarningMessage(
+                `You have both the rust-analyzer (rust-lang.rust-analyzer) and Rust (rust-lang.rust) ` +
+                    "plugins enabled. These are known to conflict and cause various functions of " +
+                    "both plugins to not work correctly. You should disable one of them.",
+                "Got it",
+            )
+            .then(() => {}, console.error);
+    }
+
+    if (vscode.extensions.getExtension("panicbit.cargo")) {
+        vscode.window
+            .showWarningMessage(
+                `You have both the rust-analyzer (rust-lang.rust-analyzer) and Cargo (panicbit.cargo) plugins enabled` +
+                    'you can disable it or set {"cargo.automaticCheck": false} in settings.json to avoid invoking cargo twice',
+                "Got it",
+            )
+            .then(() => {}, console.error);
+    }
+}