Manually remove $(BUILT_SOURCES) since no-dist-built-sources doesnt work
diff --git a/lib/dart/Makefile.am b/lib/dart/Makefile.am
index bd12a92..74f1404 100644
--- a/lib/dart/Makefile.am
+++ b/lib/dart/Makefile.am
@@ -28,6 +28,9 @@
 
 check-local: all
 
+distdir:
+	$(MAKE) $(AM_MAKEFLAGS) distdir-am
+
 dist-hook:
 	$(RM) -r $(distdir)/.pub
 	find $(distdir) -type d -name ".dart_tool" | xargs $(RM) -r