Store the async-await compiled pub code directly in the repo.

sdk/lib/_internal/pub_generated/test/serve/does_not_serve_gitignored_assets_in_a_path_dependency_test.dart

+library pub_tests;
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+import 'utils.dart';
+main() {
+  initConfig();
+  integration("doesn't serve .gitignored assets in a path dependency", () {
+    ensureGit();
+    d.dir(appPath, [d.appPubspec({
+        "foo": {
+          "path": "../foo"
+        }
+      })]).create();
+    d.git(
+        "foo",
+        [
+            d.libPubspec("foo", "1.0.0"),
+            d.dir(
+                "lib",
+                [
+                    d.file("outer.txt", "outer contents"),
+                    d.file("visible.txt", "visible"),
+                    d.dir("dir", [d.file("inner.txt", "inner contents")])]),
+            d.file(".gitignore", "/lib/outer.txt\n/lib/dir")]).create();
+    pubServe(shouldGetFirst: true);
+    requestShould404("packages/foo/outer.txt");
+    requestShould404("packages/foo/dir/inner.txt");
+    requestShouldSucceed("packages/foo/visible.txt", "visible");
+    endPubServe();
+  });
+}