Tie-break requirements with package name

This makes the ordering deterministic to improve debugging and user experience.
pypa · Nov 4, 2020 · 69a95cf · 69a95cf
1 parent 0512785
commit 69a95cf
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diff --git a/news/9100.feature.rst b/news/9100.feature.rst
@@ -0,0 +1 @@
+The new resolver now resolves packages in a deterministic order.
diff --git a/src/pip/_internal/resolution/resolvelib/provider.py b/src/pip/_internal/resolution/resolvelib/provider.py
@@ -57,7 +57,8 @@ def get_preference(
     ):
         # type: (...) -> Any
         transitive = all(parent is not None for _, parent in information)
-        return (transitive, bool(candidates))
+        key = next(iter(candidates)).name if candidates else ""
+        return (transitive, key)
 
     def find_matches(self, requirements):
         # type: (Sequence[Requirement]) -> Iterable[Candidate]