fix missing ()
@@ -84,7 +84,7 @@ class RBuildPack(PythonBuildPack):
return True
description_R = 'DESCRIPTION'
- if (not self.binder_dir and os.path.exists(description_R)
+ if ((not self.binder_dir and os.path.exists(description_R))
or 'r' in self.stencila_contexts):
if not self.checkpoint_date:
# no R snapshot date set through runtime.txt
