Revert "Try setting the working directory explicitly."

utils/pub/git_source.dart

Index: utils/pub/git_source.dart
diff --git a/utils/pub/git_source.dart b/utils/pub/git_source.dart
index c79253c436cef007aa52bf0551df341f745d9a7a..6327638d93ba54925cc3da600db4e351cab060dc 100644
--- a/utils/pub/git_source.dart
+++ b/utils/pub/git_source.dart
@@ -153,7 +153,7 @@ class GitSource extends Source {
     return ensureDir(to).chain((_) {
       var args = ["clone", from, to];
       if (mirror) args.insertRange(1, 1, "--mirror");
-      return git.run(args, workingDir: currentWorkingDir);
+      return git.run(args);
     }).transform((result) => null);
   }