Handle ISO formats with a trailing Z

Author: pfmoore

news/12338.bugfix.rst

@@ -0,0 +1 @@
+Handle a timezone indicator of Z when parsing dates in the self check.

src/pip/_internal/self_outdated_check.py

@@ -39,6 +39,15 @@ def _get_statefile_name(key: str) -> str:
     return name
 
 
+def _convert_date(isodate: str) -> datetime.datetime:
+    """Convert an ISO format string to a date.
+
+    Handles the format 2020-01-22T14:24:01Z (trailing Z)
+    which is not supported by older versions of fromisoformat.
+    """
+    return datetime.datetime.fromisoformat(isodate.replace("Z", "+00:00"))
+
+
 class SelfCheckState:
     def __init__(self, cache_dir: str) -> None:
         self._state: Dict[str, Any] = {}
@@ -73,7 +82,7 @@ def get(self, current_time: datetime.datetime) -> Optional[str]:
             return None
 
         # Determine if we need to refresh the state
-        last_check = datetime.datetime.fromisoformat(self._state["last_check"])
+        last_check = _convert_date(self._state["last_check"])
         time_since_last_check = current_time - last_check
         if time_since_last_check > _WEEK:
             return None