Merge pull request #13001 from notatallshaw/vendor-resolvelib-1.1.0

Vendor resolvelib 1.1.0

Author: notatallshaw

docs/html/topics/more-dependency-resolution.md

@@ -160,8 +160,6 @@ follows:
     explicit URL.
 * If equal, prefer if any requirement is "pinned", i.e. contains
     operator ``===`` or ``==``.
-* If equal, calculate an approximate "depth" and resolve requirements
-    closer to the user-specified requirements first.
 * Order user-specified requirements by the order they are specified.
 * If equal, prefers "non-free" requirements, i.e. contains at least one
     operator, such as ``>=`` or ``<``.

news/13001.bugfix.rst

@@ -0,0 +1,4 @@
+Resolvelib 1.1.0 fixes a known issue where pip would report a
+ResolutionImpossible error even though there is a valid solution.
+However, some very complex dependency resolutions that previously
+resolved may resolve slower or fail with an ResolutionTooDeep error.

news/resolvelib.vendor.rst

@@ -0,0 +1 @@
+Upgrade resolvelib to 1.1.0.

src/pip/_internal/resolution/resolvelib/factory.py

@@ -748,7 +748,7 @@ def get_installation_error(
         # The simplest case is when we have *one* cause that can't be
         # satisfied. We just report that case.
         if len(e.causes) == 1:
-            req, parent = e.causes[0]
+            req, parent = next(iter(e.causes))
             if req.name not in constraints:
                 return self._report_single_requirement_conflict(req, parent)
 

src/pip/_internal/resolution/resolvelib/provider.py

@@ -1,4 +1,3 @@
-import collections
 import math
 from functools import lru_cache
 from typing import (
@@ -100,7 +99,6 @@ def __init__(
         self._ignore_dependencies = ignore_dependencies
         self._upgrade_strategy = upgrade_strategy
         self._user_requested = user_requested
-        self._known_depths: Dict[str, float] = collections.defaultdict(lambda: math.inf)
 
     def identify(self, requirement_or_candidate: Union[Requirement, Candidate]) -> str:
         return requirement_or_candidate.name
@@ -124,10 +122,6 @@ def get_preference(
           explicit URL.
         * If equal, prefer if any requirement is "pinned", i.e. contains
           operator ``===`` or ``==``.
-        * If equal, calculate an approximate "depth" and resolve requirements
-          closer to the user-specified requirements first. If the depth cannot
-          by determined (eg: due to no matching parents), it is considered
-          infinite.
         * Order user-specified requirements by the order they are specified.
         * If equal, prefers "non-free" requirements, i.e. contains at least one
           operator, such as ``>=`` or ``<``.
@@ -157,23 +151,6 @@ def get_preference(
         direct = candidate is not None
         pinned = any(op[:2] == "==" for op in operators)
         unfree = bool(operators)
-
-        try:
-            requested_order: Union[int, float] = self._user_requested[identifier]
-        except KeyError:
-            requested_order = math.inf
-            if has_information:
-                parent_depths = (
-                    self._known_depths[parent.name] if parent is not None else 0.0
-                    for _, parent in information[identifier]
-                )
-                inferred_depth = min(d for d in parent_depths) + 1.0
-            else:
-                inferred_depth = math.inf
-        else:
-            inferred_depth = 1.0
-        self._known_depths[identifier] = inferred_depth
-
         requested_order = self._user_requested.get(identifier, math.inf)
 
         # Requires-Python has only one candidate and the check is basically
@@ -190,7 +167,6 @@ def get_preference(
             not direct,
             not pinned,
             not backtrack_cause,
-            inferred_depth,
             requested_order,
             not unfree,
             identifier,

src/pip/_internal/resolution/resolvelib/reporter.py

@@ -1,6 +1,6 @@
 from collections import defaultdict
 from logging import getLogger
-from typing import Any, DefaultDict
+from typing import Any, DefaultDict, Optional
 
 from pip._vendor.resolvelib.reporters import BaseReporter
 
@@ -9,7 +9,7 @@
 logger = getLogger(__name__)
 
 
-class PipReporter(BaseReporter):
+class PipReporter(BaseReporter[Requirement, Candidate, str]):
     def __init__(self) -> None:
         self.reject_count_by_package: DefaultDict[str, int] = defaultdict(int)
 
@@ -55,7 +55,7 @@ def rejecting_candidate(self, criterion: Any, candidate: Candidate) -> None:
         logger.debug(msg)
 
 
-class PipDebuggingReporter(BaseReporter):
+class PipDebuggingReporter(BaseReporter[Requirement, Candidate, str]):
     """A reporter that does an info log for every event it sees."""
 
     def starting(self) -> None:
@@ -71,7 +71,9 @@ def ending_round(self, index: int, state: Any) -> None:
     def ending(self, state: Any) -> None:
         logger.info("Reporter.ending(%r)", state)
 
-    def adding_requirement(self, requirement: Requirement, parent: Candidate) -> None:
+    def adding_requirement(
+        self, requirement: Requirement, parent: Optional[Candidate]
+    ) -> None:
         logger.info("Reporter.adding_requirement(%r, %r)", requirement, parent)
 
     def rejecting_candidate(self, criterion: Any, candidate: Candidate) -> None:

src/pip/_internal/resolution/resolvelib/resolver.py

@@ -82,7 +82,7 @@ def resolve(
             user_requested=collected.user_requested,
         )
         if "PIP_RESOLVER_DEBUG" in os.environ:
-            reporter: BaseReporter = PipDebuggingReporter()
+            reporter: BaseReporter[Requirement, Candidate, str] = PipDebuggingReporter()
         else:
             reporter = PipReporter()
         resolver: RLResolver[Requirement, Candidate, str] = RLResolver(

src/pip/_vendor/resolvelib/__init__.py

@@ -11,12 +11,13 @@
     "ResolutionTooDeep",
 ]
 
-__version__ = "1.0.1"
+__version__ = "1.1.0"
 
 
-from .providers import AbstractProvider, AbstractResolver
+from .providers import AbstractProvider
 from .reporters import BaseReporter
 from .resolvers import (
+    AbstractResolver,
     InconsistentCandidate,
     RequirementsConflicted,
     ResolutionError,