Updated comment omitted from previous commit
@@ -136,10 +136,10 @@ class InstallRequirement(object):
self._pyproject_backend = None
# Are we using PEP 517 for this requirement?
- # This can be None until load_pyproject_toml has been called,
- # after which it will have an explicit value.
- # TODO: Maybe make this a property, but if we do we'll need
- # to set the backing value based on the --use-pep517 flag.
+ # After pyproject.toml has been loaded, the only valid values are True
+ # and False. Before loading, None is valid (meaning "use the default").
+ # Setting an explicit value before loading pyproject.toml is supported,
+ # but after loading this flag should be treated as read only.
self.use_pep517 = None
# Constructors
