diff --git a/git/index/base.py b/git/index/base.py
@@ -530,7 +530,10 @@ def unmerged_blobs(self) -> Dict[PathLike, List[Tuple[StageType, Blob]]]:
            stage. That is, a file removed on the 'other' branch whose entries are at
            stage 3 will not have a stage 3 entry.
        """
-        is_unmerged_blob = lambda t: t[0] != 0
        path_map: Dict[PathLike, List[Tuple[StageType, Blob]]] = {}
        for stage, blob in self.iter_blobs(is_unmerged_blob):
            path_map.setdefault(blob.path, []).append((stage, blob))
@@ -690,12 +693,17 @@ def _store_path(self, filepath: PathLike, fprogress: Callable) -> BaseIndexEntry
            This must be ensured in the calling code.
        """
        st = os.lstat(filepath)  # Handles non-symlinks as well.
        if S_ISLNK(st.st_mode):
            # In PY3, readlink is a string, but we need bytes.
            # In PY2, it was just OS encoded bytes, we assumed UTF-8.
-            open_stream: Callable[[], BinaryIO] = lambda: BytesIO(force_bytes(os.readlink(filepath), encoding=defenc))
        else:
-            open_stream = lambda: open(filepath, "rb")
        with open_stream() as stream:
            fprogress(filepath, False, filepath)
            istream = self.repo.odb.store(IStream(Blob.type, st.st_size, stream))
@@ -1336,8 +1344,11 @@ def handle_stderr(proc: "Popen[bytes]", iter_checked_out_files: Iterable[PathLik
            kwargs["as_process"] = True
            kwargs["istream"] = subprocess.PIPE
            proc = self.repo.git.checkout_index(args, **kwargs)
            # FIXME: Reading from GIL!
-            make_exc = lambda: GitCommandError(("git-checkout-index",) + tuple(args), 128, proc.stderr.read())
            checked_out_files: List[PathLike] = []

            for path in paths:

diff --git a/git/objects/tree.py b/git/objects/tree.py
@@ -50,7 +50,9 @@

# --------------------------------------------------------

-cmp: Callable[[str, str], int] = lambda a, b: (a > b) - (a < b)


class TreeModifier:

diff --git a/pyproject.toml b/pyproject.toml
@@ -60,16 +60,14 @@ lint.select = [
    # "UP",  # See: https://docs.astral.sh/ruff/rules/#pyupgrade-up
]
lint.extend-select = [
-    # "A",     # See: https://pypi.org/project/flake8-builtins
-    "B",       # See: https://pypi.org/project/flake8-bugbear
-    "C4",      # See: https://pypi.org/project/flake8-comprehensions
-    "TCH004",  # See: https://docs.astral.sh/ruff/rules/runtime-import-in-type-checking-block/
]
lint.ignore = [
-    "E203",  # Whitespace before ':'
-    "E731",  # Do not assign a `lambda` expression, use a `def`
]
-lint.ignore-init-module-imports = true
lint.unfixable = [
    "F401",  # Module imported but unused
]

diff --git a/requirements-dev.txt b/requirements-dev.txt
@@ -1,8 +1,8 @@
--r requirements.txt
--r test-requirements.txt
-
-# For additional local testing/linting - to be added elsewhere eventually.
-ruff
-shellcheck
-pytest-icdiff
-# pytest-profiling
diff --git a/test/test_fun.py b/test/test_fun.py
@@ -243,6 +243,7 @@ def test_tree_traversal(self):
        B_old = self.rorepo.tree("1f66cfbbce58b4b552b041707a12d437cc5f400a")  # old base tree

        # Two very different trees.
        entries = traverse_trees_recursive(odb, [B_old.binsha, H.binsha], "")
        self._assert_tree_entries(entries, 2)

@@ -251,7 +252,10 @@ def test_tree_traversal(self):
        self._assert_tree_entries(oentries, 2)

        # Single tree.
-        is_no_tree = lambda i, d: i.type != "tree"
        entries = traverse_trees_recursive(odb, [B.binsha], "")
        assert len(entries) == len(list(B.traverse(predicate=is_no_tree)))
        self._assert_tree_entries(entries, 1)

diff --git a/test/test_index.py b/test/test_index.py
@@ -330,7 +330,10 @@ def test_index_file_from_tree(self, rw_repo):
        assert len([e for e in three_way_index.entries.values() if e.stage != 0])

        # ITERATE BLOBS
-        merge_required = lambda t: t[0] != 0
        merge_blobs = list(three_way_index.iter_blobs(merge_required))
        assert merge_blobs
        assert merge_blobs[0][0] in (1, 2, 3)

diff --git a/test/test_tree.py b/test/test_tree.py
@@ -126,12 +126,18 @@ def test_traverse(self):
        assert len(list(root)) == len(list(root.traverse(depth=1)))

        # Only choose trees.
-        trees_only = lambda i, d: i.type == "tree"
        trees = list(root.traverse(predicate=trees_only))
        assert len(trees) == len([i for i in root.traverse() if trees_only(i, 0)])

        # Test prune.
-        lib_folder = lambda t, d: t.path == "lib"
        pruned_trees = list(root.traverse(predicate=trees_only, prune=lib_folder))
        assert len(pruned_trees) < len(trees)
Original file line number	Diff line number	Diff line change
Expand Up		@@ -50,7 +50,9 @@

		# --------------------------------------------------------

		cmp: Callable[[str, str], int] = lambda a, b: (a > b) - (a < b)


		class TreeModifier:
Expand Down