--- a/mercurial/chgserver.py	Tue Dec 19 21:29:34 2023 +0100
+++ b/mercurial/chgserver.py	Wed Dec 20 11:23:09 2023 +0100
@@ -48,6 +48,10 @@
 import struct
 import time
 
+from typing import (
+    Optional,
+)
+
 from .i18n import _
 from .node import hex
 
@@ -628,14 +632,16 @@
 
     pollinterval = 1  # [sec]
 
+    _hashstate: Optional[hashstate]
+    _baseaddress: Optional[bytes]
+    _realaddress: Optional[bytes]
+
     def __init__(self, ui):
         self.ui = ui
 
-        # TODO: use PEP 526 syntax (`_hashstate: hashstate` at the class level)
-        #  when 3.5 support is dropped.
-        self._hashstate = None  # type: hashstate
-        self._baseaddress = None  # type: bytes
-        self._realaddress = None  # type: bytes
+        self._hashstate = None
+        self._baseaddress = None
+        self._realaddress = None
 
         self._idletimeout = ui.configint(b'chgserver', b'idletimeout')
         self._lastactive = time.time()

--- a/mercurial/error.py	Tue Dec 19 21:29:34 2023 +0100
+++ b/mercurial/error.py	Wed Dec 20 11:23:09 2023 +0100
@@ -57,7 +57,7 @@
     """
 
     def __init__(self, *args, **kw):
-        self.hint = kw.pop('hint', None)  # type: Optional[bytes]
+        self.hint: Optional[bytes] = kw.pop('hint', None)
         super(Hint, self).__init__(*args, **kw)
 
 

--- a/mercurial/i18n.py	Tue Dec 19 21:29:34 2023 +0100
+++ b/mercurial/i18n.py	Wed Dec 20 11:23:09 2023 +0100
@@ -89,7 +89,7 @@
     if message not in cache:
         if type(message) is str:
             # goofy unicode docstrings in test
-            paragraphs = message.split(u'\n\n')  # type: List[str]
+            paragraphs: List[str] = message.split(u'\n\n')
         else:
             # should be ascii, but we have unicode docstrings in test, which
             # are converted to utf-8 bytes on Python 3.

--- a/mercurial/pathutil.py	Tue Dec 19 21:29:34 2023 +0100
+++ b/mercurial/pathutil.py	Wed Dec 20 11:23:09 2023 +0100
@@ -392,4 +392,4 @@
 # rather not let our internals know that we're thinking in posix terms
 # - instead we'll let them be oblivious.
 join = posixpath.join
-dirname = posixpath.dirname  # type: Callable[[bytes], bytes]
+dirname: Callable[[bytes], bytes] = posixpath.dirname

--- a/mercurial/phases.py	Tue Dec 19 21:29:34 2023 +0100
+++ b/mercurial/phases.py	Wed Dec 20 11:23:09 2023 +0100
@@ -163,7 +163,9 @@
 _fphasesentry = struct.Struct(b'>i20s')
 
 # record phase index
-public, draft, secret = range(3)  # type: int
+public: int = 0
+draft: int = 1
+secret: int = 2
 archived = 32  # non-continuous for compatibility
 internal = 96  # non-continuous for compatibility
 allphases = (public, draft, secret, archived, internal)

--- a/mercurial/upgrade_utils/actions.py	Tue Dec 19 21:29:34 2023 +0100
+++ b/mercurial/upgrade_utils/actions.py	Wed Dec 20 11:23:09 2023 +0100
@@ -108,7 +108,7 @@
     compatible_with_share = False
 
 
-allformatvariant = []  # type: List[Type['formatvariant']]
+allformatvariant: List[Type['formatvariant']] = []
 
 
 def registerformatvariant(cls):