Add additional-packs to fix library path resolution

extensions/ql-vscode/src/cli.ts

@@ -486,17 +486,23 @@ export class CodeQLCliServer implements Disposable {
    * Finds the language that a query is analyzing.
    * @param queryUri The URI of the query
    */
-
-  // Note: this currently fails for some queries, e.g. the "example" snippets..."
-  async findLanguage(queryUri?: Uri): Promise<string> {
+  async findLanguage(workspaces: string[], queryUri?: Uri): Promise<string> {
     let language = '';
     if (queryUri) {
+      const subcommandArgs = [
+        '--format', 'bylanguage',
+        queryUri.fsPath,
+        '--additional-packs',
+        workspaces.join(path.delimiter)
+      ];
       try {
-        const JSONResults = await this.runCodeQlCliCommand(['resolve', 'queries'], ['--format', 'bylanguage', queryUri.fsPath], 'Finding query language');
+        const JSONResults = await this.runCodeQlCliCommand(['resolve', 'queries'], subcommandArgs, 'Finding query language');
 
+        // This corresponds to `codeql resolve queries <query> --format bylanguage | jq -r '.byLanguage | keys[]'`
         language = Object.keys(JSON.parse(JSONResults).byLanguage)[0];
       }
       catch (e) {
+        // Add an option to manually specify the language, in case automatic language detection fails.
         void this.logger.log('Failed to detect language. Using manual prompt instead.');
         language = await window.showQuickPick(
           ['cpp', 'csharp', 'go', 'java', 'javascript', 'python'], { placeHolder: 'Select language' }

extensions/ql-vscode/src/extension.ts

@@ -559,11 +559,13 @@ async function activateWithInstalledDistribution(
       }
     )
   );
+  // TODO: Remove this. (Temporary command to test `cliServer.findLanguage`)
   ctx.subscriptions.push(
     commandRunner('codeQL.findLanguage', async (
       uri: Uri | undefined
     ) => {
-      const language = await cliServer.findLanguage(uri || window.activeTextEditor?.document.uri);
+      const diskWorkspaceFolders = helpers.getOnDiskWorkspaceFolders();
+      const language = await cliServer.findLanguage(diskWorkspaceFolders, uri || window.activeTextEditor?.document.uri);
       void helpers.showAndLogInformationMessage(language);
     })
   );