Create binstubs for executables when activating a package.

sdk/lib/_internal/pub/test/global/binstubs/unknown_explicit_executable_test.dart

Index: sdk/lib/_internal/pub/test/global/binstubs/unknown_explicit_executable_test.dart
diff --git a/sdk/lib/_internal/pub/test/global/binstubs/unknown_explicit_executable_test.dart b/sdk/lib/_internal/pub/test/global/binstubs/unknown_explicit_executable_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..ae1e0e0f3978dd17d6311f6974d79454ee8e4c04
--- /dev/null
+++ b/sdk/lib/_internal/pub/test/global/binstubs/unknown_explicit_executable_test.dart
@@ -0,0 +1,35 @@
+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:scheduled_test/scheduled_stream.dart';
+
+import '../../../lib/src/exit_codes.dart' as exit_codes;
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+
+main() {
+  initConfig();
+  integration("errors on an unknown explicit executable", () {
+    d.dir("foo", [
+      d.pubspec({
+        "name": "foo",
+        "executables": {
+          "one": "one"
+        }
+      }),
+      d.dir("bin", [
+        d.file("one.dart", "main() => print('ok');")
+      ])
+    ]).create();
+
+    var pub = startPub(args: [
+      "global", "activate", "--source", "path", "../foo",
+      "-x", "who", "-x", "one", "--executable", "wat"
+    ]);
+
+    pub.stdout.expect(consumeThrough("Installed executable one."));
+    pub.stderr.expect("Unknown executables wat and who.");
+    pub.shouldExit(exit_codes.DATA);
+  });
+}