Fix travis builds for dartdoc (#2235)

Try and fix travis builds for dartdoc.

Author: jcollins-g

.travis.yml

@@ -5,10 +5,11 @@ dart:
   - dev
 env:
   - DARTDOC_BOT=main
-  - DARTDOC_BOT=flutter
   - DARTDOC_BOT=sdk-analyzer
+  - DARTDOC_BOT=flutter
   - DARTDOC_BOT=packages
   - DARTDOC_BOT=sdk-docs
+
 script: ./tool/travis.sh
 
 os:
@@ -19,6 +20,10 @@ matrix:
   - env: DARTDOC_BOT=main
     os: osx
     dart: dev
+  # workaround for dart-lang/dartdoc#2233
+  exclude:
+  - env: DARTDOC_BOT=flutter
+    dart: dev
 
 install:
 - ./tool/install_travis.sh

tool/grind.dart

@@ -800,8 +800,11 @@ Future<String> _buildPubPackageDocs(
   await launcher.runStreamed('pub', args);
   var cache =
       Directory(path.join(env['PUB_CACHE'], 'hosted', 'pub.dartlang.org'));
-  Directory pubPackageDir =
+  var pubPackageDirOrig =
       cache.listSync().firstWhere((e) => e.path.contains(pubPackageName));
+  var pubPackageDir = Directory.systemTemp.createTempSync(pubPackageName);
+  await copyPath(pubPackageDirOrig.path, pubPackageDir.path);
+
   if (packageMetaProvider.fromDir(pubPackageDir).requiresFlutter) {
     var flutterRepo =
         await FlutterRepo.fromExistingFlutterRepo(await cleanFlutterRepo);