diff --git a/src/pip/_internal/resolution/resolvelib/factory.py b/src/pip/_internal/resolution/resolvelib/factory.py
index 0ac8d1af9..8e1a68d16 100644
--- a/src/pip/_internal/resolution/resolvelib/factory.py
+++ b/src/pip/_internal/resolution/resolvelib/factory.py
@@ -421,7 +421,7 @@ class Factory(object):
             triggers.append(trigger)
 
         if triggers:
-            info = text_join(triggers)
+            info = text_join(sorted(triggers))
         else:
             info = "the requested packages"