[extension] Better error when submitting

extension/bwcontest/src/problemPanel.ts

@@ -104,9 +104,8 @@ export class BWPanel {
 							data.value.teamId,
 							data.value.problemId
 						);
-					} catch (reason) {
-						vscode.window.showErrorMessage('Unable to submit');
-						console.error(reason);
+					} catch (err: any) {
+						vscode.window.showErrorMessage(err.message ?? 'Submission unsuccessful');
 						break;
 					}
 					vscode.window.showInformationMessage('Submitted!');
@@ -135,8 +134,15 @@ export class BWPanel {
 						),
 						data.value.problemPascalName,
 						data.value.input
-					).then((output) => {
+					)
+						.then((output) => {
 							this._panel.webview.postMessage({ type: 'onOutput', value: output });
+						})
+						.catch(() => {
+							this._panel.webview.postMessage({
+								type: 'onOutput',
+								value: '[An error occurred while running]'
+							});
 						});
 					break;
 				}

extension/bwcontest/src/submit.ts

@@ -58,6 +58,6 @@ export async function submitProblem(
 		throw Error('Failed to post submission');
 	}
 	if (!res.data.success) {
-		throw Error('Submission post unsuccessful');
+		throw Error(res.data.message ?? 'Unknown error');
 	}
 }