diff --git a/CHANGES b/CHANGES
index 0e5784113..9dfca4ee3 100644
--- a/CHANGES
+++ b/CHANGES
@@ -79,7 +79,7 @@ Bugs fixed
 Testing
 --------
 
-Release 3.5.1 (in development)
+Release 3.5.2 (in development)
 ==============================
 
 Dependencies
@@ -100,6 +100,20 @@ Bugs fixed
 Testing
 --------
 
+Release 3.5.1 (released Feb 16, 2021)
+=====================================
+
+Bugs fixed
+----------
+
+* #8883: autodoc: AttributeError is raised on assigning __annotations__ on
+  read-only class
+* #8884: html: minified js stemmers not included in the distributed package
+* #8885: html: AttributeError is raised if CSS/JS files are installed via
+  :confval:`html_context`
+* #8880: viewcode: ExtensionError is raised on incremental build after
+  unparsable python module found
+
 Release 3.5.0 (released Feb 14, 2021)
 =====================================
 
diff --git a/MANIFEST.in b/MANIFEST.in
index 54da42895..1114ca19f 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -22,6 +22,7 @@ recursive-include sphinx/texinputs_win *
 recursive-include sphinx/themes *
 recursive-include sphinx/locale *.js *.pot *.po *.mo
 recursive-include sphinx/search/non-minified-js *.js
+recursive-include sphinx/search/minified-js *.js
 recursive-include sphinx/ext/autosummary/templates *
 recursive-include tests *
 recursive-include utils *
diff --git a/sphinx/builders/html/__init__.py b/sphinx/builders/html/__init__.py
index f818566ac..a68594a6d 100644
--- a/sphinx/builders/html/__init__.py
+++ b/sphinx/builders/html/__init__.py
@@ -1035,8 +1035,20 @@ class StandaloneHTMLBuilder(Builder):
             templatename = newtmpl
 
         # sort JS/CSS before rendering HTML
-        ctx['script_files'].sort(key=lambda js: js.priority)
-        ctx['css_files'].sort(key=lambda js: js.priority)
+        try:
+            # Convert script_files to list to support non-list script_files (refs: #8889)
+            ctx['script_files'] = sorted(list(ctx['script_files']), key=lambda js: js.priority)
+        except AttributeError:
+            # Skip sorting if users modifies script_files directly (maybe via `html_context`).
+            # refs: #8885
+            #
+            # Note: priority sorting feature will not work in this case.
+            pass
+
+        try:
+            ctx['css_files'] = sorted(list(ctx['css_files']), key=lambda css: css.priority)
+        except AttributeError:
+            pass
 
         try:
             output = self.templates.render(templatename, ctx)
diff --git a/sphinx/ext/autodoc/__init__.py b/sphinx/ext/autodoc/__init__.py
index 699787fb6..2ac24ebff 100644
--- a/sphinx/ext/autodoc/__init__.py
+++ b/sphinx/ext/autodoc/__init__.py
@@ -1377,7 +1377,7 @@ class FunctionDocumenter(DocstringSignatureMixin, ModuleLevelDocumenter):  # typ
             params[0] = params[0].replace(annotation=typ)
             try:
                 func.__signature__ = sig.replace(parameters=params)  # type: ignore
-            except TypeError:
+            except (AttributeError, TypeError):
                 # failed to update signature (ex. built-in or extension types)
                 return
 
@@ -2156,7 +2156,7 @@ class MethodDocumenter(DocstringSignatureMixin, ClassLevelDocumenter):  # type:
             params[1] = params[1].replace(annotation=typ)
             try:
                 func.__signature__ = sig.replace(parameters=params)  # type: ignore
-            except TypeError:
+            except (AttributeError, TypeError):
                 # failed to update signature (ex. built-in or extension types)
                 return
 
@@ -2422,7 +2422,7 @@ class AttributeDocumenter(GenericAliasMixin, NewTypeMixin, SlotsMixin,  # type:
                             annotations[attrname] = annotation
                 except (AttributeError, PycodeError):
                     pass
-        except TypeError:
+        except (AttributeError, TypeError):
             # Failed to set __annotations__ (built-in, extensions, etc.)
             pass
 
diff --git a/sphinx/ext/viewcode.py b/sphinx/ext/viewcode.py
index 21cff6a03..6bedf2e1c 100644
--- a/sphinx/ext/viewcode.py
+++ b/sphinx/ext/viewcode.py
@@ -152,7 +152,11 @@ def env_merge_info(app: Sphinx, env: BuildEnvironment, docnames: Iterable[str],
 def env_purge_doc(app: Sphinx, env: BuildEnvironment, docname: str) -> None:
     modules = getattr(env, '_viewcode_modules', {})
 
-    for modname, (code, tags, used, refname) in list(modules.items()):
+    for modname, entry in list(modules.items()):
+        if entry is False:
+            continue
+
+        code, tags, used, refname = entry
         for fullname in list(used):
             if used[fullname] == docname:
                 used.pop(fullname)
diff --git a/tests/test_build_html.py b/tests/test_build_html.py
index 3df65245c..fccf9cc6a 100644
--- a/tests/test_build_html.py
+++ b/tests/test_build_html.py
@@ -1597,7 +1597,14 @@ def test_html_codeblock_linenos_style_table(app):
     app.build()
     content = (app.outdir / 'index.html').read_text()
 
-    assert '<div class="linenodiv"><pre>1\n2\n3\n4</pre></div>' in content
+    pygments_version = tuple(LooseVersion(pygments.__version__).version)
+    if pygments_version >= (2, 8):
+        assert ('<div class="linenodiv"><pre><span class="normal">1</span>\n'
+                '<span class="normal">2</span>\n'
+                '<span class="normal">3</span>\n'
+                '<span class="normal">4</span></pre></div>') in content
+    else:
+        assert '<div class="linenodiv"><pre>1\n2\n3\n4</pre></div>' in content
 
 
 @pytest.mark.sphinx('html', testroot='reST-code-block',