[25.11.x] Fix empty channels being passed to solver handling _h_env creation

conda_build/environ.py

@@ -25,7 +25,6 @@
 )
 from conda.base.context import context, reset_context
 from conda.common.io import env_vars
-from conda.core.index import LAST_CHANNEL_URLS
 from conda.core.link import PrefixSetup, UnlinkLinkTransaction
 from conda.core.package_cache_data import PackageCacheData, ProgressiveFetchExtract
 from conda.core.prefix_data import PrefixData
@@ -38,7 +37,7 @@
     UnsatisfiableError,
 )
 from conda.gateways.disk.create import TemporaryDirectory
-from conda.models.channel import Channel, prioritize_channels
+from conda.models.channel import Channel
 from conda.models.match_spec import MatchSpec
 from conda.models.records import PackageRecord
 
@@ -62,6 +61,8 @@
     from pathlib import Path
     from typing import Any, TypedDict
 
+    from conda.core.index import Index
+
     from .config import Config
     from .metadata import MetaData
 
@@ -1262,7 +1263,7 @@ def get_pinned_deps(m, section):
 #       checks for this name in the call stack explicitly.
 def install_actions(
     prefix: str | os.PathLike | Path,
-    index,
+    index: Index,
     specs: Iterable[str | MatchSpec],
     subdir: str | None = None,
 ) -> InstallActionsType:
@@ -1280,25 +1281,8 @@ def install_actions(
         },
         callback=reset_context,
     ):
-        # a hack since in conda-build we don't track channel_priority_map
-        channels: tuple[Channel, ...] | None
-        subdirs: tuple[str, ...] | None
-        if LAST_CHANNEL_URLS:
-            channel_priority_map = prioritize_channels(LAST_CHANNEL_URLS)
-            # tuple(dict.fromkeys(...)) removes duplicates while preserving input order.
-            channels = tuple(
-                dict.fromkeys(Channel(url) for url in channel_priority_map)
-            )
-            subdirs = (
-                tuple(
-                    dict.fromkeys(
-                        subdir for channel in channels if (subdir := channel.subdir)
-                    )
-                )
-                or context.subdirs
-            )
-        else:
-            channels = subdirs = None
+        channels: tuple[Channel, ...] | None = tuple(index.expanded_channels) or None
+        subdirs: tuple[str, ...] | None = tuple(index._subdirs) or None
 
         mspecs = tuple(MatchSpec(spec) for spec in specs)
 

conda_build/index.py

@@ -6,9 +6,9 @@
 import os
 from functools import partial
 from os.path import dirname
-from typing import TYPE_CHECKING
 
 from conda.base.context import context
+from conda.core.index import Index
 from conda.exceptions import CondaHTTPError
 from conda.utils import url_path
 
@@ -17,9 +17,6 @@
     get_logger,
 )
 
-if TYPE_CHECKING:
-    from conda.models.channels import Channel
-
 try:
     from conda_index.index import update_index as _update_index
 except ImportError:
@@ -28,16 +25,6 @@
     )
 
 
-try:
-    from conda.core.index import Index
-except ImportError:
-    # FUTURE: remove for `conda >=24.9`
-    from conda.core.index import get_index
-
-    def Index(channels: tuple[str | Channel, ...] = (), *args, **kwargs) -> dict:  # type: ignore[no-redef]
-        return get_index(channel_urls=channels, *args, **kwargs)
-
-
 log = get_logger(__name__)
 
 

conda_build/inspect_pkg.py

@@ -16,6 +16,7 @@
 from conda.api import Solver
 from conda.base.context import context
 from conda.cli.common import specs_from_args
+from conda.core.index import Index
 from conda.core.prefix_data import PrefixData
 from conda.models.records import PrefixRecord
 
@@ -37,12 +38,6 @@
     package_has_file,
 )
 
-try:
-    from conda.core.index import Index
-except ImportError:
-    # FUTURE: remove for `conda >=24.9`
-    from conda_build.index import Index
-
 if TYPE_CHECKING:
     from collections.abc import Iterable
     from typing import Literal

conda_build/skeletons/cpan.py

@@ -21,6 +21,7 @@
 from os.path import basename, dirname, exists, join
 
 import requests
+from conda.core.index import Index
 from conda.exceptions import CondaError, CondaHTTPError
 from conda.gateways.connection.download import TmpDownload, download
 from conda.gateways.disk.create import TemporaryDirectory
@@ -33,12 +34,6 @@
 from ..variants import get_default_variant
 from ..version import _parse as parse_version
 
-try:
-    from conda.core.index import Index
-except ImportError:
-    # FUTURE: remove for `conda >=24.9`
-    from conda_build.index import Index
-
 CPAN_META = """\
 {{% set name = "{packagename}" %}}
 {{% set version = "{version}" %}}

news/5857-empty-channels.md

@@ -0,0 +1,19 @@
+### Enhancements
+
+* <news item>
+
+### Bug fixes
+
+* Prevent empty channel lists from being passed to host environment creation. (#5857)
+
+### Deprecations
+
+* Remove fallback imports for `conda.core.index.Index`. (#5857)
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>