linter: avoid a crash when running benchmarks w/o internet

Change-Id: Idda61b9632ac2127e58ca85627bc712fba7e7d25
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/352986
Commit-Queue: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Auto-Submit: Samuel Rawlins <srawlins@google.com>
diff --git a/pkg/linter/tool/util/score_utils.dart b/pkg/linter/tool/util/score_utils.dart
index a2bb390..24aae6c 100644
--- a/pkg/linter/tool/util/score_utils.dart
+++ b/pkg/linter/tool/util/score_utils.dart
@@ -45,8 +45,12 @@
 
 // TODO(pq): update `scorecard.dart` to reuse these fetch functions.
 Future<List<String>> _fetchLints(String url) async {
-  var req = await http.get(Uri.parse(url));
-  return _readLints(req.body);
+  try {
+    var req = await http.get(Uri.parse(url));
+    return _readLints(req.body);
+  } on http.ClientException {
+    return [];
+  }
 }
 
 Future<List<String>> _readCoreLints() async => _fetchLints(