Stop using and deprecate ISpiderLoader.

docs/news.rst

@@ -3,6 +3,23 @@
 Release notes
 =============
 
+Scrapy VERSION (unreleased)
+---------------------------
+
+Backward-incompatible changes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+-   The following runtime usage of zope.interface_ interfaces is removed:
+
+    - :class:`~scrapy.spiderloader.SpiderLoader` and
+      :class:`~scrapy.spiderloader.DummySpiderLoader` are no longer marked
+      as implementing the ``ISpiderLoader`` interface.
+
+    - :func:`~scrapy.spiderloader.get_spider_loader` no longer checks that the
+      configured spider loader implements the ``ISpiderLoader`` interface.
+
+    (:issue:`6585`, :issue:`TBD`)
+
 .. _release-2.17.0:
 
 Scrapy 2.17.0 (2026-07-07)

scrapy/interfaces.py

@@ -1,7 +1,17 @@
+# pragma: no file cover
 # pylint: disable=no-method-argument,no-self-argument
+import warnings
 
 from zope.interface import Interface
 
+from scrapy.exceptions import ScrapyDeprecationWarning
+
+warnings.warn(
+    "The scrapy.interfaces module is deprecated.",
+    ScrapyDeprecationWarning,
+    stacklevel=2,
+)
+
 
 class ISpiderLoader(Interface):
     def from_settings(settings):

scrapy/spiderloader.py

@@ -5,9 +5,6 @@ import warnings
 from collections import defaultdict
 from typing import TYPE_CHECKING, Protocol, cast
 
-from zope.interface import implementer
-
-from scrapy.interfaces import ISpiderLoader
 from scrapy.utils.misc import load_object, walk_modules_iter
 from scrapy.utils.spider import iter_spider_classes
 
@@ -45,7 +42,6 @@ class SpiderLoaderProtocol(Protocol):
         """Return the list of spiders names that can handle the given request"""
 
 
-@implementer(ISpiderLoader)
 class SpiderLoader:
     """
     SpiderLoader is a class which locates and loads spiders
@@ -131,7 +127,6 @@ class SpiderLoader:
         return list(self._spiders.keys())
 
 
-@implementer(ISpiderLoader)
 class DummySpiderLoader:
     """A dummy spider loader that does not load any spiders."""