diff --git a/distutils/_modified.py b/distutils/_modified.py
index f64cab7d..0e7494c1 100644
--- a/distutils/_modified.py
+++ b/distutils/_modified.py
@@ -7,7 +7,9 @@
 from collections.abc import Callable, Iterable
 from typing import Literal, TypeVar
 
-from jaraco.functools import splat
+from jaraco.functools import (
+    splat,  # jaraco/jaraco.functools#30
+)
 
 from .compat.py39 import zip_strict
 from .errors import DistutilsFileError
diff --git a/distutils/archive_util.py b/distutils/archive_util.py
index d860f552..2bd1e4e9 100644
--- a/distutils/archive_util.py
+++ b/distutils/archive_util.py
@@ -6,19 +6,24 @@
 from __future__ import annotations
 
 import os
+from collections.abc import Callable
+from types import ModuleType
 from typing import Literal, overload
 
-try:
-    import zipfile
-except ImportError:
-    zipfile = None
-
-
 from ._log import log
 from .dir_util import mkpath
 from .errors import DistutilsExecError
 from .spawn import spawn
 
+zipfile: ModuleType | None = None
+try:
+    import zipfile
+except ImportError:
+    pass
+
+# mypy: disable-error-code="attr-defined"
+# We have to be more flexible than simply checking for `sys.platform != "win32"`
+# https://github.com/python/mypy/issues/1393
 try:
     from pwd import getpwnam
 except ImportError:
@@ -85,16 +90,15 @@ def make_tarball(
         'xz': 'xz',
         None: '',
     }
-    compress_ext = {'gzip': '.gz', 'bzip2': '.bz2', 'xz': '.xz'}
+    compress_ext = {'gzip': '.gz', 'bzip2': '.bz2', 'xz': '.xz', None: ''}
 
     # flags for compression program, each element of list will be an argument
-    if compress is not None and compress not in compress_ext.keys():
+    if compress not in compress_ext.keys():
         raise ValueError(
-            "bad value for 'compress': must be None, 'gzip', 'bzip2', 'xz'"
+            f"bad value for 'compress': must be one of {list(compress_ext.keys())!r}"
         )
 
-    archive_name = base_name + '.tar'
-    archive_name += compress_ext.get(compress, '')
+    archive_name = base_name + '.tar' + compress_ext[compress]
 
     mkpath(os.path.dirname(archive_name), dry_run=dry_run)
 
@@ -116,7 +120,10 @@ def _set_uid_gid(tarinfo):
         return tarinfo
 
     if not dry_run:
-        tar = tarfile.open(archive_name, f'w|{tar_compression[compress]}')
+        tar = tarfile.open(
+            archive_name,
+            f'w|{tar_compression[compress]}',  # type: ignore[call-overload] # Typeshed doesn't allow non-literal string here
+        )
         try:
             tar.add(base_dir, filter=_set_uid_gid)
         finally:
@@ -191,7 +198,9 @@ def make_zipfile(  # noqa: C901
     return zip_filename
 
 
-ARCHIVE_FORMATS = {
+ARCHIVE_FORMATS: dict[
+    str, tuple[Callable[..., str], list[tuple[str, str | None]], str]
+] = {
     'gztar': (make_tarball, [('compress', 'gzip')], "gzip'ed tar-file"),
     'bztar': (make_tarball, [('compress', 'bzip2')], "bzip2'ed tar-file"),
     'xztar': (make_tarball, [('compress', 'xz')], "xz'ed tar-file"),
@@ -270,7 +279,7 @@ def make_archive(
     if base_dir is None:
         base_dir = os.curdir
 
-    kwargs = {'dry_run': dry_run}
+    kwargs: dict[str, str | bool | None] = {'dry_run': dry_run}
 
     try:
         format_info = ARCHIVE_FORMATS[format]
diff --git a/distutils/cmd.py b/distutils/cmd.py
index 241621bd..c783e302 100644
--- a/distutils/cmd.py
+++ b/distutils/cmd.py
@@ -12,7 +12,7 @@
 import sys
 from abc import abstractmethod
 from collections.abc import Callable, MutableSequence
-from typing import TYPE_CHECKING, Any, ClassVar, TypeVar, overload
+from typing import TYPE_CHECKING, Any, ClassVar, TypeVar, cast, overload
 
 from . import _modified, archive_util, dir_util, file_util, util
 from ._log import log
@@ -70,6 +70,8 @@ class Command:
         list[tuple[str, str, str]] | list[tuple[str, str | None, str]]
     ] = []
 
+    description = ""
+
     # -- Creation/initialization methods -------------------------------
 
     def __init__(self, dist: Distribution) -> None:
@@ -107,7 +109,7 @@ def __init__(self, dist: Distribution) -> None:
         # timestamps, but methods defined *here* assume that
         # 'self.force' exists for all commands.  So define it here
         # just to be safe.
-        self.force = None
+        self.force: bool | None = None
 
         # The 'help' flag is just used for command-line parsing, so
         # none of that complicated bureaucracy is needed.
@@ -330,7 +332,8 @@ def get_finalized_command(self, command: str, create: bool = True) -> Command:
         'command', call its 'ensure_finalized()' method, and return the
         finalized command object.
         """
-        cmd_obj = self.distribution.get_command_obj(command, create)
+        # TODO: Raise a more descriptive error when cmd_obj is None ?
+        cmd_obj = cast(Command, self.distribution.get_command_obj(command, create))
         cmd_obj.ensure_finalized()
         return cmd_obj
 
@@ -504,7 +507,7 @@ def make_archive(
         owner: str | None = None,
         group: str | None = None,
     ) -> str:
-        return archive_util.make_archive(
+        return archive_util.make_archive(  # type: ignore[misc] # Mypy bailed out
             base_name,
             format,
             root_dir,
@@ -533,7 +536,7 @@ def make_file(
         timestamp checks.
         """
         if skip_msg is None:
-            skip_msg = f"skipping {outfile} (inputs unchanged)"
+            skip_msg = f"skipping {outfile!r} (inputs unchanged)"
 
         # Allow 'infiles' to be a single string
         if isinstance(infiles, str):
@@ -542,7 +545,7 @@ def make_file(
             raise TypeError("'infiles' must be a string, or a list or tuple of strings")
 
         if exec_msg is None:
-            exec_msg = "generating {} from {}".format(outfile, ', '.join(infiles))
+            exec_msg = f"generating {outfile!r} from {', '.join(infiles)}"
 
         # If 'outfile' must be regenerated (either because it doesn't
         # exist, is out-of-date, or the 'force' flag is true) then
diff --git a/distutils/command/bdist_rpm.py b/distutils/command/bdist_rpm.py
index 357b4e86..542c70b7 100644
--- a/distutils/command/bdist_rpm.py
+++ b/distutils/command/bdist_rpm.py
@@ -288,7 +288,7 @@ def run(self) -> None:  # noqa: C901
             spec_dir = self.dist_dir
             self.mkpath(spec_dir)
         else:
-            rpm_dir = {}
+            rpm_dir: dict[str, str] = {}
             for d in ('SOURCES', 'SPECS', 'BUILD', 'RPMS', 'SRPMS'):
                 rpm_dir[d] = os.path.join(self.rpm_base, d)
                 self.mkpath(rpm_dir[d])
diff --git a/distutils/command/build_py.py b/distutils/command/build_py.py
index a20b076f..154e25b6 100644
--- a/distutils/command/build_py.py
+++ b/distutils/command/build_py.py
@@ -360,7 +360,7 @@ def build_modules(self) -> None:
             self.build_module(module, module_file, package)
 
     def build_packages(self) -> None:
-        for package in self.packages:
+        for package in self.packages or ():
             # Get list of (package, module, module_file) tuples based on
             # scanning the package directory.  'package' is only included
             # in the tuple so that 'find_modules()' and
diff --git a/distutils/command/install.py b/distutils/command/install.py
index 8421d54e..7b4c553c 100644
--- a/distutils/command/install.py
+++ b/distutils/command/install.py
@@ -256,8 +256,8 @@ def initialize_options(self) -> None:
         # These select only the installation base; it's up to the user to
         # specify the installation scheme (currently, that means supplying
         # the --install-{platlib,purelib,scripts,data} options).
-        self.install_base = None
-        self.install_platbase = None
+        self.install_base: str | None = None
+        self.install_platbase: str | None = None
         self.root: str | None = None
 
         # These options are the actual installation directories; if not
diff --git a/distutils/command/install_lib.py b/distutils/command/install_lib.py
index 2aababf8..d7d0c51f 100644
--- a/distutils/command/install_lib.py
+++ b/distutils/command/install_lib.py
@@ -120,7 +120,7 @@ def install(self) -> list[str] | Any:
             self.warn(
                 f"'{self.build_dir}' does not exist -- no Python modules to install"
             )
-            return
+            return None
         return outfiles
 
     def byte_compile(self, files) -> None:
diff --git a/distutils/compilers/C/base.py b/distutils/compilers/C/base.py
index 93385e13..cdb085ed 100644
--- a/distutils/compilers/C/base.py
+++ b/distutils/compilers/C/base.py
@@ -414,7 +414,7 @@ def _fix_compile_args(
         output_dir: str | None,
         macros: list[_Macro] | None,
         include_dirs: list[str] | tuple[str, ...] | None,
-    ) -> tuple[str, list[_Macro], list[str]]:
+    ) -> tuple[str | None, list[_Macro], list[str]]:
         """Typecheck and fix-up some of the arguments to the 'compile()'
         method, and return fixed-up values.  Specifically: if 'output_dir'
         is None, replaces it with 'self.output_dir'; ensures that 'macros'
@@ -466,7 +466,7 @@ def _prep_compile(self, sources, output_dir, depends=None):
 
     def _fix_object_args(
         self, objects: list[str] | tuple[str, ...], output_dir: str | None
-    ) -> tuple[list[str], str]:
+    ) -> tuple[list[str], str | None]:
         """Typecheck and fix up some arguments supplied to various methods.
         Specifically: ensure that 'objects' is a list; if output_dir is
         None, replace with self.output_dir.  Return fixed versions of
diff --git a/distutils/dir_util.py b/distutils/dir_util.py
index d9782602..1d7b9db7 100644
--- a/distutils/dir_util.py
+++ b/distutils/dir_util.py
@@ -57,10 +57,11 @@ def mkpath(name: pathlib.Path, mode=0o777, verbose=True, dry_run=False) -> None:
     if verbose and not name.is_dir():
         log.info("creating %s", name)
 
-    try:
-        dry_run or name.mkdir(mode=mode, parents=True, exist_ok=True)
-    except OSError as exc:
-        raise DistutilsFileError(f"could not create '{name}': {exc.args[-1]}")
+    if not dry_run:
+        try:
+            name.mkdir(mode=mode, parents=True, exist_ok=True)
+        except OSError as exc:
+            raise DistutilsFileError(f"could not create '{name}': {exc.args[-1]}")
 
 
 @mkpath.register
diff --git a/distutils/dist.py b/distutils/dist.py
index b9552a8b..39b2c686 100644
--- a/distutils/dist.py
+++ b/distutils/dist.py
@@ -23,6 +23,7 @@
     Literal,
     TypeVar,
     Union,
+    cast,
     overload,
 )
 
@@ -576,11 +577,10 @@ def _parse_command_opts(self, parser, args):  # noqa: C901
             hasattr(cmd_class, 'user_options')
             and isinstance(cmd_class.user_options, list)
         ):
-            msg = (
-                "command class %s must provide "
+            raise DistutilsClassError(
+                f"command class {cmd_class} must provide "
                 "'user_options' attribute (a list of tuples)"
             )
-            raise DistutilsClassError(msg % cmd_class)
 
         # If the command class has a list of negative alias options,
         # merge it in with the global negative aliases.
@@ -849,7 +849,7 @@ def get_command_class(self, command: str) -> type[Command]:
                 continue
 
             try:
-                klass = getattr(module, klass_name)
+                klass = cast(type[Command], getattr(module, klass_name))
             except AttributeError:
                 raise DistutilsModuleError(
                     f"invalid command '{command}' (no class '{klass_name}' in module '{module_name}')"
@@ -865,9 +865,7 @@ def get_command_obj(
         self, command: str, create: Literal[True] = True
     ) -> Command: ...
     @overload
-    def get_command_obj(
-        self, command: str, create: Literal[False]
-    ) -> Command | None: ...
+    def get_command_obj(self, command: str, create: bool) -> Command | None: ...
     def get_command_obj(self, command: str, create: bool = True) -> Command | None:
         """Return the command object for 'command'.  Normally this object
         is cached on a previous call to 'get_command_obj()'; if no command
@@ -1198,7 +1196,7 @@ def _read_list(name):
         self.description = _read_field('summary')
 
         if 'keywords' in msg:
-            self.keywords = _read_field('keywords').split(',')
+            self.keywords = _read_field('keywords').split(',')  # type:ignore[union-attr] # Manually checked
 
         self.platforms = _read_list('platform')
         self.classifiers = _read_list('classifier')
diff --git a/distutils/extension.py b/distutils/extension.py
index f5141126..d61ce77e 100644
--- a/distutils/extension.py
+++ b/distutils/extension.py
@@ -144,8 +144,7 @@ def __init__(
 
         # If there are unknown keyword options, warn about them
         if len(kw) > 0:
-            options = [repr(option) for option in kw]
-            options = ', '.join(sorted(options))
+            options = ', '.join(sorted([repr(option) for option in kw]))
             msg = f"Unknown Extension options: {options}"
             warnings.warn(msg)
 
diff --git a/distutils/fancy_getopt.py b/distutils/fancy_getopt.py
index 7d079118..e9407fee 100644
--- a/distutils/fancy_getopt.py
+++ b/distutils/fancy_getopt.py
@@ -249,6 +249,7 @@ def getopt(self, args: Sequence[str] | None = None, object=None):  # noqa: C901
             raise DistutilsArgError(msg)
 
         for opt, val in opts:
+            value: int | str = val
             if len(opt) == 2 and opt[0] == '-':  # it's a short option
                 opt = self.short2long[opt[1]]
             else:
@@ -260,21 +261,21 @@ def getopt(self, args: Sequence[str] | None = None, object=None):  # noqa: C901
                 opt = alias
 
             if not self.takes_arg[opt]:  # boolean option?
-                assert val == '', "boolean option can't have value"
+                assert value == '', "boolean option can't have value"
                 alias = self.negative_alias.get(opt)
                 if alias:
                     opt = alias
-                    val = 0
+                    value = 0
                 else:
-                    val = 1
+                    value = 1
 
             attr = self.attr_name[opt]
             # The only repeating option at the moment is 'verbose'.
             # It has a negative option -q quiet, which should set verbose = False.
-            if val and self.repeat.get(attr) is not None:
-                val = getattr(object, attr, 0) + 1
-            setattr(object, attr, val)
-            self.option_order.append((opt, val))
+            if value and self.repeat.get(attr) is not None:
+                value = getattr(object, attr, 0) + 1
+            setattr(object, attr, value)
+            self.option_order.append((opt, value))
 
         # for opts
         if created_object:
diff --git a/distutils/filelist.py b/distutils/filelist.py
index 70dc0fde..b50d654a 100644
--- a/distutils/filelist.py
+++ b/distutils/filelist.py
@@ -200,7 +200,7 @@ def process_template_line(self, line: str) -> None:  # noqa: C901
     @overload
     def include_pattern(
         self,
-        pattern: str,
+        pattern: str | None,
         anchor: bool = True,
         prefix: str | None = None,
         is_regex: Literal[False] = False,
@@ -224,7 +224,7 @@ def include_pattern(
     ) -> bool: ...
     def include_pattern(
         self,
-        pattern: str | re.Pattern,
+        pattern: str | re.Pattern | None,
         anchor: bool = True,
         prefix: str | None = None,
         is_regex: bool = False,
@@ -262,7 +262,7 @@ def include_pattern(
         if self.allfiles is None:
             self.findall()
 
-        for name in self.allfiles:
+        for name in self.allfiles:  # type: ignore[union-attr] # Calling findall fills allfiles
             if pattern_re.search(name):
                 self.debug_print(" adding " + name)
                 self.files.append(name)
@@ -272,7 +272,7 @@ def include_pattern(
     @overload
     def exclude_pattern(
         self,
-        pattern: str,
+        pattern: str | None,
         anchor: bool = True,
         prefix: str | None = None,
         is_regex: Literal[False] = False,
@@ -296,7 +296,7 @@ def exclude_pattern(
     ) -> bool: ...
     def exclude_pattern(
         self,
-        pattern: str | re.Pattern,
+        pattern: str | re.Pattern | None,
         anchor: bool = True,
         prefix: str | None = None,
         is_regex: bool = False,
diff --git a/distutils/sysconfig.py b/distutils/sysconfig.py
index 7ddc869a..be2016d8 100644
--- a/distutils/sysconfig.py
+++ b/distutils/sysconfig.py
@@ -324,6 +324,14 @@ def customize_compiler(compiler: CCompiler) -> None:
             'AR',
             'ARFLAGS',
         )
+        assert isinstance(cc, str)
+        assert isinstance(cxx, str)
+        assert isinstance(cflags, str)
+        assert isinstance(ccshared, str)
+        assert isinstance(ldshared, str)
+        assert isinstance(ldcxxshared, str)
+        assert isinstance(ar_flags, str)
+        assert isinstance(shlib_suffix, str)
 
         cxxflags = cflags
 
@@ -355,6 +363,7 @@ def customize_compiler(compiler: CCompiler) -> None:
         ldcxxshared = _add_flags(ldcxxshared, 'CPP')
 
         ar = os.environ.get('AR', ar)
+        assert isinstance(ar, str)
 
         archiver = ar + ' ' + os.environ.get('ARFLAGS', ar_flags)
         cc_cmd = cc + ' ' + cflags
@@ -376,7 +385,7 @@ def customize_compiler(compiler: CCompiler) -> None:
         if 'RANLIB' in os.environ and compiler.executables.get('ranlib', None):
             compiler.set_executables(ranlib=os.environ['RANLIB'])
 
-        compiler.shared_lib_extension = shlib_suffix
+        compiler.shared_lib_extension = shlib_suffix  # type: ignore[misc] # Assigning to ClassVar
 
 
 def get_config_h_filename() -> str:
@@ -549,8 +558,8 @@ def expand_makefile_vars(s, vars):
 @overload
 def get_config_vars() -> dict[str, str | int]: ...
 @overload
-def get_config_vars(arg: str, /, *args: str) -> list[str | int]: ...
-def get_config_vars(*args: str) -> list[str | int] | dict[str, str | int]:
+def get_config_vars(arg: str, /, *args: str) -> list[str | int | None]: ...
+def get_config_vars(*args: str) -> list[str | int | None] | dict[str, str | int]:
     """With no arguments, return a dictionary of all configuration
     variables relevant for the current platform.  Generally this includes
     everything needed to build extensions and install both pure modules and
diff --git a/distutils/tests/unix_compat.py b/distutils/tests/unix_compat.py
index a5d9ee45..88b5296a 100644
--- a/distutils/tests/unix_compat.py
+++ b/distutils/tests/unix_compat.py
@@ -1,10 +1,15 @@
+from __future__ import annotations
+
 import sys
+from types import ModuleType
 
+grp: ModuleType | None = None
+pwd: ModuleType | None = None
 try:
     import grp
     import pwd
 except ImportError:
-    grp = pwd = None
+    pass
 
 import pytest
 
diff --git a/distutils/util.py b/distutils/util.py
index 17e86fed..62235cc9 100644
--- a/distutils/util.py
+++ b/distutils/util.py
@@ -151,7 +151,9 @@ def change_root(
         if not os.path.isabs(pathname):
             return os.path.join(new_root, pathname)
         else:
-            return os.path.join(new_root, pathname[1:])
+            # type-ignore: This makes absolutes os.Pathlike unsupported in this branch.
+            # Either this or we don't support bytes-based paths, or we complexify this branch.
+            return os.path.join(new_root, pathname[1:])  # type: ignore[index]
 
     elif os.name == 'nt':
         (drive, path) = os.path.splitdrive(pathname)
@@ -232,14 +234,9 @@ def grok_environment_error(exc: object, prefix: str = "error: ") -> str:
 
 
 # Needed by 'split_quoted()'
-_wordchars_re = _squote_re = _dquote_re = None
-
-
-def _init_regex():
-    global _wordchars_re, _squote_re, _dquote_re
-    _wordchars_re = re.compile(rf'[^\\\'\"{string.whitespace} ]*')
-    _squote_re = re.compile(r"'(?:[^'\\]|\\.)*'")
-    _dquote_re = re.compile(r'"(?:[^"\\]|\\.)*"')
+_wordchars_re = re.compile(rf'[^\\\'\"{string.whitespace} ]*')
+_squote_re = re.compile(r"'(?:[^'\\]|\\.)*'")
+_dquote_re = re.compile(r'"(?:[^"\\]|\\.)*"')
 
 
 def split_quoted(s: str) -> list[str]:
@@ -256,8 +253,6 @@ def split_quoted(s: str) -> list[str]:
     # This is a nice algorithm for splitting up a single string, since it
     # doesn't require character-by-character examination.  It was a little
     # bit of a brain-bender to get it working right, though...
-    if _wordchars_re is None:
-        _init_regex()
 
     s = s.strip()
     words = []
@@ -265,6 +260,7 @@ def split_quoted(s: str) -> list[str]:
 
     while s:
         m = _wordchars_re.match(s, pos)
+        assert m is not None
         end = m.end()
         if end == len(s):
             words.append(s[:end])
@@ -305,9 +301,6 @@ def split_quoted(s: str) -> list[str]:
     return words
 
 
-# split_quoted ()
-
-
 def execute(
     func: Callable[[Unpack[_Ts]], object],
     args: tuple[Unpack[_Ts]],
diff --git a/mypy.ini b/mypy.ini
index 146222a5..3f67a0f6 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -16,20 +16,12 @@ disable_error_code =
 
 # local
 
+	# Code that is too dynamic using variable command names;
+	# and code that uses platform checks mypy doesn't understand
+	attr-defined,
 	# TODO: Resolve and re-enable these gradually
 	operator,
-	attr-defined,
 	arg-type,
-	assignment,
-	call-overload,
-	return-value,
-	index,
-	type-var,
-	func-returns-value,
-	union-attr,
-	str-bytes-safe,
-	misc,
-	has-type,
 
 # stdlib's test module is not typed on typeshed
 [mypy-test.*]