_get_index_content's session arg must be a kw arg
@@ -443,7 +443,7 @@ def _make_index_content(
)
-def _get_index_content(link: Link, session: PipSession) -> Optional["IndexContent"]:
+def _get_index_content(link: Link, *, session: PipSession) -> Optional["IndexContent"]:
url = link.url.split("#", 1)[0]
# Check for VCS schemes that do not support lookup as web pages.
