Pass context.exclude_newer to libmambapy Database

Convert the exclude_newer duration/timestamp from conda's config
into a Unix timestamp cutoff and pass it to libmambapy's Database
constructor as exclude_newer_timestamp. This enables native
--exclude-newer filtering in the libmamba solver backend.

Depends on:
- conda/conda#15761 (exclude_newer config + parse_duration_to_seconds)
- mamba-org/mamba#4228 (exclude_newer_timestamp in Database::Settings)

Author: jezdez

conda_libmamba_solver/index.py

@@ -75,13 +75,15 @@
 
 import logging
 import os
+import time
 from dataclasses import dataclass
 from functools import partial
 from pathlib import Path
 from typing import TYPE_CHECKING
 
 from conda.base.constants import KNOWN_SUBDIRS, REPODATA_FN, ChannelPriority
 from conda.base.context import context
+from conda.cli.helpers import parse_duration_to_seconds
 from conda.common.compat import on_win
 from conda.common.io import DummyExecutor, ThreadLimitedThreadPoolExecutor, time_recorder
 from conda.common.url import path_to_url, remove_auth, split_anaconda_token
@@ -347,10 +349,21 @@ def _init_db(self) -> Database:
             home_dir=str(Path.home()),
             current_working_dir=os.getcwd(),
         )
-        db = Database(params)
+        db = Database(
+            params,
+            exclude_newer_timestamp=self._exclude_newer_timestamp(),
+        )
         db.set_logger(logger_callback)
         return db
 
+    @staticmethod
+    def _exclude_newer_timestamp():
+        """Convert context.exclude_newer to a Unix timestamp for libmambapy."""
+        value = context.exclude_newer
+        if not value:
+            return None
+        return int(time.time() - parse_duration_to_seconds(value))
+
     def _load_channels(
         self,
         urls_to_channel: dict[str, Channel] | None = None,

news/exclude-newer

@@ -0,0 +1,21 @@
+### Enhancements
+
+* Pass `context.exclude_newer` to libmambapy's `Database` as
+  `exclude_newer_timestamp`, enabling native `--exclude-newer` support
+  when the upstream mamba PR lands. (#15759)
+
+### Bug fixes
+
+* <news item>
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>

tests/test_index.py

@@ -208,3 +208,23 @@ def test_load_channels_order(shard_factory):
     assert [
         repo.channel.canonical_name for repo in shard_enabled_index.repos
     ] == expected_output_channels
+
+
+def test_exclude_newer_timestamp_unset(monkeypatch: pytest.MonkeyPatch):
+    monkeypatch.setattr(context, "exclude_newer", "")
+    assert LibMambaIndexHelper._exclude_newer_timestamp() is None
+
+
+def test_exclude_newer_timestamp_duration(monkeypatch: pytest.MonkeyPatch):
+    monkeypatch.setattr(context, "exclude_newer", "7d")
+    result = LibMambaIndexHelper._exclude_newer_timestamp()
+    assert result is not None
+    expected = int(time.time() - 7 * 86400)
+    assert abs(result - expected) < 2
+
+
+def test_exclude_newer_timestamp_zero_duration(monkeypatch: pytest.MonkeyPatch):
+    monkeypatch.setattr(context, "exclude_newer", "0d")
+    result = LibMambaIndexHelper._exclude_newer_timestamp()
+    assert result is not None
+    assert abs(result - int(time.time())) < 2