feat(resolver): move cooldown filtering to find_matches, log summary at INFO

Move cooldown filtering from is_satisfied_by() into find_matches(),
aligning with resolvelib's intended API: is_satisfied_by() handles
specifier/constraint matching for backtracking, while find_matches()
produces the filtered candidate list.

Per-candidate cooldown detail remains at DEBUG (gated behind
DEBUG_RESOLVER). A single INFO summary line per package lists all
blocked versions, keeping production logs concise while still
surfacing enforcement.

Add E2E assertions verifying that enforcement messages appear in logs
for all cooldown test scenarios (basic, transitive, prebuilt, gitlab).

Co-Authored-By: Claude <claude@anthropic.com>

Author: ryanpetrello

e2e/test_bootstrap_cooldown.sh

@@ -59,6 +59,12 @@ if ! find "$OUTDIR/wheels-repo/downloads/" -name 'stevedore-5.3.0*.whl' | grep -
   pass=false
 fi
 
+# The cooldown must have logged that it blocked stevedore version(s).
+if ! grep -q "cooldown blocked .* version(s):" "$OUTDIR/bootstrap-flag.log"; then
+  echo "FAIL (flag): no cooldown enforcement message for stevedore found in log" 1>&2
+  pass=false
+fi
+
 # --- Pass 2: enforce the same cooldown via environment variable (FROMAGER_MIN_RELEASE_AGE) ---
 
 # Wipe output so the second run starts clean.
@@ -82,4 +88,9 @@ if ! find "$OUTDIR/wheels-repo/downloads/" -name 'stevedore-5.3.0*.whl' | grep -
   pass=false
 fi
 
+if ! grep -q "cooldown blocked .* version(s):" "$OUTDIR/bootstrap-envvar.log"; then
+  echo "FAIL (envvar): no cooldown enforcement message for stevedore found in log" 1>&2
+  pass=false
+fi
+
 $pass

e2e/test_bootstrap_cooldown_gitlab.sh

@@ -75,4 +75,10 @@ if ! grep -q "GitLabTagProvider" "$OUTDIR/bootstrap.log"; then
   pass=false
 fi
 
+# The cooldown must have logged that it blocked python-gitlab version(s).
+if ! grep -q "cooldown blocked .* version(s):" "$OUTDIR/bootstrap.log"; then
+  echo "FAIL: no cooldown enforcement message for python-gitlab found in log" 1>&2
+  pass=false
+fi
+
 $pass

e2e/test_bootstrap_cooldown_prebuilt.sh

@@ -62,4 +62,10 @@ if find "$OUTDIR/sdists-repo/" \( -name 'stevedore*.tar.gz' -o -name 'stevedore*
   pass=false
 fi
 
+# The cooldown must have logged that it blocked stevedore version(s).
+if ! grep -q "cooldown blocked .* version(s):" "$OUTDIR/bootstrap.log"; then
+  echo "FAIL: no cooldown enforcement message for stevedore found in log" 1>&2
+  pass=false
+fi
+
 $pass

e2e/test_bootstrap_cooldown_transitive.sh

@@ -69,4 +69,10 @@ if ! find "$OUTDIR/wheels-repo/downloads/" -name 'pbr-6.1.1*.whl' | grep -q .; t
   pass=false
 fi
 
+# The cooldown must have logged that it blocked pbr version(s).
+if ! grep -q "cooldown blocked .* version(s):" "$OUTDIR/bootstrap.log"; then
+  echo "FAIL: no cooldown enforcement message for pbr found in log" 1>&2
+  pass=false
+fi
+
 $pass

src/fromager/resolver.py

@@ -680,9 +680,6 @@ def is_satisfied_by(self, requirement: Requirement, candidate: Candidate) -> boo
                 )
             return False
 
-        if self.is_blocked_by_cooldown(candidate):
-            return False
-
         return True
 
     def is_blocked_by_cooldown(self, candidate: Candidate) -> bool:
@@ -700,10 +697,9 @@ def is_blocked_by_cooldown(self, candidate: Candidate) -> bool:
                 if candidate.name not in BaseProvider._cooldown_unsupported_warned:
                     BaseProvider._cooldown_unsupported_warned.add(candidate.name)
                     logger.warning(
-                        "%s: release-age cooldown cannot be enforced — upload "
+                        "release-age cooldown cannot be enforced — upload "
                         "timestamp support is not yet implemented for %s; "
                         "cooldown check skipped",
-                        candidate.name,
                         self.get_provider_description(),
                     )
                 return False
@@ -712,8 +708,7 @@ def is_blocked_by_cooldown(self, candidate: Candidate) -> bool:
             # Fail closed: we cannot verify the age of this candidate, so reject it.
             if DEBUG_RESOLVER:
                 logger.debug(
-                    "%s: skipping %s — upload_time unknown, required for cooldown",
-                    candidate.name,
+                    "skipping %s — upload_time unknown, required for cooldown",
                     candidate.version,
                 )
             return True
@@ -727,8 +722,7 @@ def is_blocked_by_cooldown(self, candidate: Candidate) -> bool:
             if DEBUG_RESOLVER:
                 age = self.cooldown.bootstrap_time - candidate.upload_time
                 logger.debug(
-                    "%s: skipping %s uploaded %s ago (cooldown: %s)",
-                    candidate.name,
+                    "skipping %s uploaded %s ago (cooldown: %s)",
                     candidate.version,
                     age,
                     self.cooldown.min_age,
@@ -809,6 +803,17 @@ def find_matches(
                 identifier, requirements, incompatibilities, candidate
             )
         ]
+        # Apply cooldown filtering after specifier/constraint validation
+        blocked = [c for c in candidates if self.is_blocked_by_cooldown(c)]
+        if blocked:
+            for b in blocked:
+                candidates.remove(b)
+            versions = ", ".join(str(b.version) for b in blocked)
+            logger.info(
+                "cooldown blocked %d version(s): %s",
+                len(blocked),
+                versions,
+            )
         if not candidates:
             raise resolvelib.resolvers.ResolverException(
                 self._get_no_match_error_message(identifier, requirements)

tests/test_cooldown.py

@@ -10,7 +10,6 @@
 import pathlib
 import re
 import typing
-from collections import defaultdict
 
 import pytest
 import requests_mock
@@ -117,10 +116,8 @@ def test_cooldown_filters_recent_version(
         candidate = result.mapping["test-pkg"]
         # 2.0.0 is 2 days old (within cooldown); 1.3.2 is 11 days old (outside).
         assert str(candidate.version) == "1.3.2"
-        # 2.0.0 should be logged as skipped; 1.3.2 should not.
-        assert "skipping 2.0.0" in caplog.text
-        assert "cooldown" in caplog.text
-        assert "skipping 1.3.2" not in caplog.text
+        # 2.0.0 should be logged as blocked; 1.3.2 should not appear in the summary.
+        assert "cooldown blocked 1 version(s): 2.0.0" in caplog.text
 
 
 def test_cooldown_disabled_selects_latest() -> None:
@@ -171,17 +168,11 @@ def test_cooldown_rejects_candidate_without_upload_time(
         upload_time=None,
     )
     provider = resolver.PyPIProvider(cooldown=_COOLDOWN)
-    req = Requirement("test-pkg")
-    requirements: typing.Any = defaultdict(list)
-    requirements["test-pkg"].append(req)
-    incompatibilities: typing.Any = defaultdict(list)
 
     with caplog.at_level(logging.DEBUG, logger="fromager.resolver"):
-        result = provider.validate_candidate(
-            "test-pkg", requirements, incompatibilities, candidate
-        )
+        result = provider.is_blocked_by_cooldown(candidate)
 
-    assert result is False
+    assert result is True
     assert "upload_time unknown" in caplog.text
     assert "1.0.0" in caplog.text
 
@@ -567,8 +558,7 @@ def test_gitlab_cooldown_filters_recent_tag(
         candidate = result.mapping["test-pkg"]
         # v0.0.3 (2025-05-14) is inside the 7-day window; v0.0.2 is the next newest.
         assert str(candidate.version) == "0.0.2"
-        assert "skipping 0.0.3" in caplog.text
-        assert "cooldown" in caplog.text
+        assert "cooldown blocked 1 version(s): 0.0.3" in caplog.text
 
 
 def test_gitlab_cooldown_disabled_selects_latest() -> None:
@@ -639,17 +629,11 @@ def test_github_cooldown_skips_with_warning(
         url="https://github.com/example/pkg/archive/v1.0.0.tar.gz",
         upload_time=None,
     )
-    req = Requirement("test-pkg")
-    requirements: typing.Any = defaultdict(list)
-    requirements["test-pkg"].append(req)
-    incompatibilities: typing.Any = defaultdict(list)
 
     with caplog.at_level(logging.WARNING, logger="fromager.resolver"):
-        result = provider.validate_candidate(
-            "test-pkg", requirements, incompatibilities, candidate
-        )
+        result = provider.is_blocked_by_cooldown(candidate)
 
-    assert result is True
+    assert result is False
     assert "cooldown cannot be enforced" in caplog.text