diff --git a/.github/workflows/pythonpackage.yml b/.github/workflows/pythonpackage.yml
@@ -95,15 +95,13 @@ jobs:
       continue-on-error: true
 
     - name: Check types with mypy
+      if: matrix.python-version != '3.7' && matrix.python-version != '3.8'
       run: |
         mypy --python-version="${PYTHON_VERSION%t}"  # Version only, with no "t" for free-threaded.
       env:
         MYPY_FORCE_COLOR: "1"
         TERM: "xterm-256color"  # For color: https://github.com/python/mypy/issues/13817
         PYTHON_VERSION: ${{ matrix.python-version }}
-      # With new versions of mypy new issues might arise. This is a problem if there is
-      # nobody able to fix them, so we have to ignore errors until that changes.
-      continue-on-error: true
 
     - name: Test with pytest
       run: |

diff --git a/git/config.py b/git/config.py
@@ -574,7 +574,7 @@ def _included_paths(self) -> List[Tuple[str, str]]:
                 if keyword.endswith("/i"):
                     value = re.sub(
                         r"[a-zA-Z]",
-                        lambda m: "[{}{}]".format(m.group().lower(), m.group().upper()),
+                        lambda m: f"[{m.group().lower()!r}{m.group().upper()!r}]",
                         value,
                     )
                 if self._repo.git_dir:
@@ -633,8 +633,6 @@ def read(self) -> None:  # type: ignore[override]
                 file_path = cast(IO[bytes], file_path)
                 self._read(file_path, file_path.name)
             else:
-                # Assume a path if it is not a file-object.
-                file_path = cast(PathLike, file_path)
                 try:
                     with open(file_path, "rb") as fp:
                         file_ok = True
@@ -768,7 +766,7 @@ def _assure_writable(self, method_name: str) -> None:
         if self.read_only:
             raise IOError("Cannot execute non-constant method %s.%s" % (self, method_name))
 
-    def add_section(self, section: str) -> None:
+    def add_section(self, section: "cp._SectionName") -> None:
         """Assures added options will stay in order."""
         return super().add_section(section)
 

diff --git a/git/diff.py b/git/diff.py
@@ -23,13 +23,14 @@
     List,
     Match,
     Optional,
+    Sequence,
     Tuple,
     TYPE_CHECKING,
     TypeVar,
     Union,
     cast,
 )
-from git.types import Literal, PathLike
+from git.types import PathLike, Literal
 
 if TYPE_CHECKING:
     from subprocess import Popen
@@ -289,7 +290,7 @@ class DiffIndex(List[T_Diff]):
     The class improves the diff handling convenience.
     """
 
-    change_type = ("A", "C", "D", "R", "M", "T")
+    change_type: Sequence[Literal["A", "C", "D", "R", "M", "T"]] = ("A", "C", "D", "R", "M", "T")  # noqa: F821
     """Change type invariant identifying possible ways a blob can have changed:
 
     * ``A`` = Added

diff --git a/git/index/typ.py b/git/index/typ.py
@@ -192,7 +192,7 @@ def from_base(cls, base: "BaseIndexEntry") -> "IndexEntry":
             Instance of type :class:`BaseIndexEntry`.
         """
         time = pack(">LL", 0, 0)
-        return IndexEntry((base.mode, base.binsha, base.flags, base.path, time, time, 0, 0, 0, 0, 0))
+        return IndexEntry((base.mode, base.binsha, base.flags, base.path, time, time, 0, 0, 0, 0, 0))  # type: ignore[arg-type]
 
     @classmethod
     def from_blob(cls, blob: Blob, stage: int = 0) -> "IndexEntry":
@@ -211,5 +211,5 @@ def from_blob(cls, blob: Blob, stage: int = 0) -> "IndexEntry":
                 0,
                 0,
                 blob.size,
-            )
+            )  # type: ignore[arg-type]
         )
diff --git a/git/objects/commit.py b/git/objects/commit.py
@@ -900,7 +900,7 @@ def co_authors(self) -> List[Actor]:
         if self.message:
             results = re.findall(
                 r"^Co-authored-by: (.*) <(.*?)>$",
-                self.message,
+                str(self.message),
                 re.MULTILINE,
             )
             for author in results:

diff --git a/git/objects/submodule/base.py b/git/objects/submodule/base.py
@@ -66,7 +66,7 @@
 if TYPE_CHECKING:
     from git.index import IndexFile
     from git.objects.commit import Commit
-    from git.refs import Head
+    from git.refs import Head, RemoteReference
     from git.repo import Repo
 
 # -----------------------------------------------------------------------------
@@ -355,7 +355,7 @@ def _clone_repo(
             module_checkout_path = osp.join(str(repo.working_tree_dir), path)
 
         if url.startswith("../"):
-            remote_name = repo.active_branch.tracking_branch().remote_name
+            remote_name = cast("RemoteReference", repo.active_branch.tracking_branch()).remote_name
             repo_remote_url = repo.remote(remote_name).url
             url = os.path.join(repo_remote_url, url)
 

diff --git a/git/refs/head.py b/git/refs/head.py
@@ -22,7 +22,6 @@
 from git.types import Commit_ish, PathLike
 
 if TYPE_CHECKING:
-    from git.objects import Commit
     from git.refs import RemoteReference
     from git.repo import Repo
 
@@ -44,9 +43,6 @@ class HEAD(SymbolicReference):
 
     __slots__ = ()
 
-    # TODO: This can be removed once SymbolicReference.commit has static type hints.
-    commit: "Commit"
-
     def __init__(self, repo: "Repo", path: PathLike = _HEAD_NAME) -> None:
         if path != self._HEAD_NAME:
             raise ValueError("HEAD instance must point to %r, got %r" % (self._HEAD_NAME, path))
@@ -149,7 +145,7 @@ class Head(Reference):
     k_config_remote_ref = "merge"  # Branch to merge from remote.
 
     @classmethod
-    def delete(cls, repo: "Repo", *heads: "Union[Head, str]", force: bool = False, **kwargs: Any) -> None:
+    def delete(cls, repo: "Repo", *heads: "Union[Head, str]", force: bool = False, **kwargs: Any) -> None:  # type: ignore[override]
         """Delete the given heads.
 
         :param force:

diff --git a/git/refs/log.py b/git/refs/log.py
@@ -145,7 +145,7 @@ def from_line(cls, line: bytes) -> "RefLogEntry":
         actor = Actor._from_string(info[82 : email_end + 1])
         time, tz_offset = parse_date(info[email_end + 2 :])  # skipcq: PYL-W0621
 
-        return RefLogEntry((oldhexsha, newhexsha, actor, (time, tz_offset), msg))
+        return RefLogEntry((oldhexsha, newhexsha, actor, (time, tz_offset), msg))  # type: ignore [arg-type]
 
 
 class RefLog(List[RefLogEntry], Serializable):

diff --git a/git/refs/symbolic.py b/git/refs/symbolic.py
@@ -916,8 +916,7 @@ def from_path(cls: Type[T_References], repo: "Repo", path: PathLike) -> T_Refere
             SymbolicReference,
         ):
             try:
-                instance: T_References
-                instance = ref_type(repo, path)
+                instance = cast(T_References, ref_type(repo, path))
                 if instance.__class__ is SymbolicReference and instance.is_detached:
                     raise ValueError("SymbolicRef was detached, we drop it")
                 else:

diff --git a/git/refs/tag.py b/git/refs/tag.py
@@ -45,8 +45,8 @@ class TagReference(Reference):
     _common_default = "tags"
     _common_path_default = Reference._common_path_default + "/" + _common_default
 
-    @property
-    def commit(self) -> "Commit":  # type: ignore[override]  # LazyMixin has unrelated commit method
+    @property  # type: ignore[misc]
+    def commit(self) -> "Commit":  # LazyMixin has unrelated commit method
         """:return: Commit object the tag ref points to
 
         :raise ValueError:
@@ -80,8 +80,8 @@ def tag(self) -> Union["TagObject", None]:
         return None
 
     # Make object read-only. It should be reasonably hard to adjust an existing tag.
-    @property
-    def object(self) -> AnyGitObject:  # type: ignore[override]
+    @property  # type: ignore[misc]
+    def object(self) -> AnyGitObject:
         return Reference._get_object(self)
 
     @classmethod

diff --git a/git/repo/base.py b/git/repo/base.py
@@ -684,11 +684,7 @@ def _config_reader(
         git_dir: Optional[PathLike] = None,
     ) -> GitConfigParser:
         if config_level is None:
-            files = [
-                self._get_config_path(cast(Lit_config_levels, f), git_dir)
-                for f in self.config_level
-                if cast(Lit_config_levels, f)
-            ]
+            files = [self._get_config_path(f, git_dir) for f in self.config_level if f]
         else:
             files = [self._get_config_path(config_level, git_dir)]
         return GitConfigParser(files, read_only=True, repo=self)
@@ -1484,7 +1480,7 @@ def clone(
             self.common_dir,
             path,
             type(self.odb),
-            progress,
+            progress,  # type: ignore[arg-type]
             multi_options,
             allow_unsafe_protocols=allow_unsafe_protocols,
             allow_unsafe_options=allow_unsafe_options,
@@ -1545,7 +1541,7 @@ def clone_from(
             url,
             to_path,
             GitCmdObjectDB,
-            progress,
+            progress,  # type: ignore[arg-type]
             multi_options,
             allow_unsafe_protocols=allow_unsafe_protocols,
             allow_unsafe_options=allow_unsafe_options,

diff --git a/git/repo/fun.py b/git/repo/fun.py
@@ -286,7 +286,7 @@ def rev_parse(repo: "Repo", rev: str) -> AnyGitObject:
             # END handle refname
         else:
             if ref is not None:
-                obj = cast("Commit", ref.commit)
+                obj = ref.commit
             # END handle ref
         # END initialize obj on first token
 

diff --git a/git/types.py b/git/types.py
@@ -13,7 +13,6 @@
     Sequence as Sequence,
     Tuple,
     TYPE_CHECKING,
-    Type,
     TypeVar,
     Union,
 )
@@ -130,7 +129,8 @@
 https://git-scm.com/docs/gitglossary#def_object_type
 """
 
-Lit_commit_ish: Type[Literal["commit", "tag"]]
+if TYPE_CHECKING:
+    Lit_commit_ish = Literal["commit", "tag"]
 """Deprecated. Type of literal strings identifying typically-commitish git object types.
 
 Prior to a bugfix, this type had been defined more broadly. Any usage is in practice

diff --git a/git/util.py b/git/util.py
@@ -1143,7 +1143,7 @@ def _obtain_lock(self) -> None:
         # END endless loop
 
 
-class IterableList(List[T_IterableObj]):
+class IterableList(List[T_IterableObj]):  # type: ignore[type-var]
     """List of iterable objects allowing to query an object by id or by named index::
 
      heads = repo.heads
@@ -1214,14 +1214,14 @@ def __getitem__(self, index: Union[SupportsIndex, int, slice, str]) -> T_Iterabl
             raise ValueError("Index should be an int or str")
         else:
             try:
-                return getattr(self, index)
+                return getattr(self, cast(str, index))
             except AttributeError as e:
-                raise IndexError("No item found with id %r" % (self._prefix + index)) from e
+                raise IndexError(f"No item found with id {self._prefix}{index}") from e
         # END handle getattr
 
     def __delitem__(self, index: Union[SupportsIndex, int, slice, str]) -> None:
         delindex = cast(int, index)
-        if not isinstance(index, int):
+        if isinstance(index, str):
             delindex = -1
             name = self._prefix + index
             for i, item in enumerate(self):

diff --git a/pyproject.toml b/pyproject.toml
@@ -19,7 +19,6 @@ testpaths = "test"  # Space separated list of paths from root e.g test tests doc
 # filterwarnings ignore::WarningType  # ignores those warnings
 
 [tool.mypy]
-python_version = "3.8"
 files = ["git/", "test/deprecation/"]
 disallow_untyped_defs = true
 no_implicit_optional = true

diff --git a/test-requirements.txt b/test-requirements.txt
@@ -1,7 +1,7 @@
 coverage[toml]
 ddt >= 1.1.1, != 1.4.3
 mock ; python_version < "3.8"
-mypy
+mypy==1.18.2 ; python_version >= "3.9" # pin mypy version to avoid new errors
 pre-commit
 pytest >= 7.3.1
 pytest-cov

diff --git a/test/deprecation/test_types.py b/test/deprecation/test_types.py
@@ -36,7 +36,7 @@ def test_can_access_lit_commit_ish_but_it_is_not_usable() -> None:
     assert 'Literal["commit", "tag"]' in message, "Has new definition."
     assert "GitObjectTypeString" in message, "Has new type name for old definition."
 
-    _: Lit_commit_ish = "commit"  # type: ignore[valid-type]
+    _: Lit_commit_ish = "commit"
 
     # It should be as documented (even though deliberately unusable in static checks).
     assert Lit_commit_ish == Literal["commit", "tag"]

diff --git a/test/lib/helper.py b/test/lib/helper.py
@@ -149,7 +149,7 @@ def repo_creator(self):
             os.chdir(rw_repo.working_dir)
             try:
                 return func(self, rw_repo)
-            except:  # noqa: E722 B001
+            except:  # noqa: E722
                 _logger.info("Keeping repo after failure: %s", repo_dir)
                 repo_dir = None
                 raise
@@ -309,7 +309,7 @@ def remote_repo_creator(self):
                     with cwd(rw_repo.working_dir):
                         try:
                             return func(self, rw_repo, rw_daemon_repo)
-                        except:  # noqa: E722 B001
+                        except:  # noqa: E722
                             _logger.info(
                                 "Keeping repos after failure: \n  rw_repo_dir: %s \n  rw_daemon_repo_dir: %s",
                                 rw_repo_dir,

diff --git a/test/test_remote.py b/test/test_remote.py
@@ -44,7 +44,7 @@
 class TestRemoteProgress(RemoteProgress):
     __slots__ = ("_seen_lines", "_stages_per_op", "_num_progress_messages")
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
         self._seen_lines = []
         self._stages_per_op = {}
@@ -103,6 +103,9 @@ def assert_received_message(self):
         assert self._num_progress_messages
 
 
+TestRemoteProgress.__test__ = False  # type: ignore
+
+
 class TestRemote(TestBase):
     def tearDown(self):
         gc.collect()

diff --git a/test/test_submodule.py b/test/test_submodule.py
@@ -58,6 +58,7 @@ def update(self, op, cur_count, max_count, message=""):
         print(op, cur_count, max_count, message)
 
 
+TestRootProgress.__test__ = False
 prog = TestRootProgress()
 
 
@@ -932,7 +933,7 @@ def assert_exists(sm, value=True):
         csm.repo.index.commit("Have to commit submodule change for algorithm to pick it up")
         assert csm.url == "bar"
 
-        self.assertRaises(
+        self.assertRaises(  # noqa: B017
             Exception,
             rsm.update,
             recursive=True,