Short circuit when there's nothing to report
@@ -539,6 +539,9 @@ class InstallCommand(RequirementCommand):
def _warn_about_conflicts(self, conflict_details):
# type: (ConflictDetails) -> None
package_set, (missing, conflicting) = conflict_details
+ if not missing and not conflicting:
+ return
+
parts = [] # type: List[str]
# NOTE: There is some duplication here, with commands/check.py
