commit 91dcfc5dd2c6d32c2256dd7cadabc2d57f2fa6dd
author Jonah Williams <jonahwilliams@users.noreply.github.com> Mon Mar 19 10:53:04 2018 -0700
committer GitHub <noreply@github.com> Mon Mar 19 10:53:04 2018 -0700
tree c963b4ce5a33724c7be1bcff033724842437674d
parent d6bac5fd4a6d131c6d33ce45b63dce721710e490

stderr can be null or empty string (#15701)

packages/flutter_tools/lib/src/ios/mac.dart

diff --git a/packages/flutter_tools/lib/src/ios/mac.dart b/packages/flutter_tools/lib/src/ios/mac.dart
index aff5667..fd34572 100644
--- a/packages/flutter_tools/lib/src/ios/mac.dart
+++ b/packages/flutter_tools/lib/src/ios/mac.dart
@@ -158,7 +158,7 @@
         // This command will error if additional components need to be installed in
         // xcode 9.2 and above.
         final ProcessResult result = processManager.runSync(<String>['/usr/bin/xcrun', 'simctl', 'list']);
-        _isSimctlInstalled = result.stderr == null;
+        _isSimctlInstalled = result.stderr == null || result.stderr == '';
       } on ProcessException {
         _isSimctlInstalled = false;
       }