Clear record_dependencies for each document (#10855)

sphinx/builders/__init__.py

@@ -10,6 +10,7 @@ from typing import (TYPE_CHECKING, Any, Dict, Iterable, List, Optional, Sequence
 
 from docutils import nodes
 from docutils.nodes import Node
+from docutils.utils import DependencyList
 
 from sphinx.config import Config
 from sphinx.deprecation import RemovedInSphinx70Warning
@@ -490,6 +491,9 @@ class Builder:
         filename = self.env.doc2path(docname)
         filetype = get_filetype(self.app.config.source_suffix, filename)
         publisher = self.app.registry.get_publisher(self.app, filetype)
+        # record_dependencies is mutable even though it is in settings,
+        # explicitly re-initialise for each document
+        publisher.settings.record_dependencies = DependencyList()
         with sphinx_domains(self.env), rst.default_role(docname, self.config.default_role):
             # set up error_handler for the target document
             codecs.register_error('sphinx', UnicodeDecodeErrorHandler(docname))  # type: ignore

tests/roots/test-environment-record-dependencies/api.rst

@@ -0,0 +1,4 @@
+API
+===
+
+.. automodule:: example_module

tests/roots/test-environment-record-dependencies/conf.py

@@ -0,0 +1,5 @@
+import os
+import sys
+
+sys.path.insert(0, os.path.abspath('.'))
+extensions = ['sphinx.ext.autodoc']

tests/roots/test-environment-record-dependencies/example_module.py

@@ -0,0 +1,2 @@
+def example_function():
+    return 42

tests/roots/test-environment-record-dependencies/index.rst

@@ -0,0 +1,3 @@
+.. toctree::
+
+    api

tests/test_environment_record_dependencies.py

@@ -0,0 +1,10 @@
+"""Tests for ``record_dependencies``."""
+
+import pytest
+
+
+@pytest.mark.sphinx('html', testroot='environment-record-dependencies')
+def test_record_dependencies_cleared(app):
+    app.builder.read()
+    assert app.env.dependencies['index'] == set()
+    assert app.env.dependencies['api'] == {'example_module.py'}