chore(build): fix all mypy errors in setup.py (#17963)

## Description

Fix a few lint errors in setup.py. Discovered when working on #17959.

## Changes
- Add proper type annotations to LibraryDownload class attributes (name, version, url_root, available_releases, translate_suffix), resolving var-annotated and assignment errors in subclasses.
- Suppress cmake.CMAKE_BIN_DIR attr-defined errors (runtime-only attribute not declared in the cmake package stubs).
- Suppress method-assign errors for intentional debug-instrumentation monkey-patching of CustomBuildExt methods.
- Wrap src.suffix in bool() to fix return type mismatch in CMakeExtension.get_sources.

## Testing

* commit passed pre-commit hooks
* CI


Co-authored-by: vlad.scherbich <vlad.scherbich@datadoghq.com>

Author: vlad-scherbich

mypy.ini

@@ -43,6 +43,17 @@ no_implicit_reexport = false
 ignore_errors = true
 no_implicit_reexport = false
 
+[mypy-setup]
+check_untyped_defs = true
+disallow_untyped_defs = false
+disallow_incomplete_defs = false
+disallow_untyped_calls = false
+disallow_untyped_decorators = false
+disallow_subclassing_any = false
+warn_return_any = false
+no_implicit_reexport = false
+disallow_any_generics = false
+
 # docs/conf.py is treated as module "conf" since docs/ has no __init__.py.
 
 [mypy-conf]

setup.py

@@ -37,7 +37,7 @@
     # ORDER MATTERS
     # Import this after setuptools or it will fail
     from Cython.Build import cythonize
-    import Cython.Distutils
+    from Cython.Distutils.extension import Extension as CythonExtension
 except ImportError:
     raise ImportError(
         "Failed to import Cython modules. This can happen under versions of pip older than 18 that don't "
@@ -208,8 +208,6 @@ def wrapper(*args, **kwargs):
                         # These often indicate temporary network issues
                         is_retriable = True
                         error_code = f"subprocess exit code {e.returncode}"
-                    else:
-                        error_code = type(e).__name__
 
                     if not is_retriable:
                         print(f"ERROR: Operation failed (non-retriable {error_code}): {e}")
@@ -299,7 +297,7 @@ def is_64_bit_python():
 
 
 class PatchedDistribution(Distribution):
-    def __init__(self, attrs=None):
+    def __init__(self, attrs: t.Optional[dict[str, t.Any]] = None) -> None:
         super().__init__(attrs)
         # Tell ext_hashes about your manually-built Rust artifact
 
@@ -322,7 +320,7 @@ def __init__(self, attrs=None):
 
 
 class ExtensionHashes(build_ext):
-    def run(self):
+    def run(self) -> None:
         try:
             dist = self.distribution
             for ext in chain(dist.ext_modules, getattr(dist, "rust_extensions", [])):
@@ -395,7 +393,7 @@ def run(self):
 class CustomBuildRust(build_rust):
     """Custom build_rust command that handles dedup_headers and header copying."""
 
-    def initialize_options(self):
+    def initialize_options(self) -> None:
         super().initialize_options()
 
     def is_installed(self, bin_file):
@@ -427,7 +425,7 @@ def cargo_install_with_retry():
 
             cargo_install_with_retry()
 
-    def run(self):
+    def run(self) -> None:
         """Run the build process with additional post-processing."""
 
         has_profiling_feature = False
@@ -466,13 +464,13 @@ class LibraryDownload:
     CACHE_DIR = Path(os.getenv("DD_SETUP_CACHE_DIR", HERE / ".download_cache"))
     USE_CACHE = os.getenv("DD_SETUP_CACHE_DOWNLOADS", "1").lower() in ("1", "yes", "on", "true")
 
-    name = None
-    download_dir = Path.cwd()
-    version = None
-    url_root = None
-    available_releases = {}
-    expected_checksums = None
-    translate_suffix = {}
+    name: t.Optional[str] = None
+    download_dir: Path = Path.cwd()
+    version: t.Optional[str] = None
+    url_root: t.Optional[str] = None
+    available_releases: dict[str, list[str]] = {}
+    expected_checksums: t.Optional[dict[str, dict[str, str]]] = None
+    translate_suffix: dict[str, tuple[str, ...]] = {}
 
     @classmethod
     def download_artifacts(cls):
@@ -565,10 +563,10 @@ def download_file(url, dest):
             # Open the tarfile first to get the files needed.
             # This could be solved with "r:gz" mode, that allows random access
             # but that approach does not work on Windows
-            with tarfile.open(filename, "r|gz", errorlevel=2) as tar:
+            with tarfile.open(filename, mode="r|gz", errorlevel=2) as tar:
                 dynfiles = [c for c in tar.getmembers() if c.name.endswith(suffixes)]
 
-            with tarfile.open(filename, "r|gz", errorlevel=2) as tar:
+            with tarfile.open(filename, mode="r|gz", errorlevel=2) as tar:
                 tar.extractall(members=dynfiles, path=HERE)
                 Path(HERE / archive_dir).rename(arch_dir)
 
@@ -588,7 +586,7 @@ def download_file(url, dest):
             (download_dir / ".version").write_text(cls.version)
 
     @classmethod
-    def run(cls):
+    def run(cls) -> None:
         cls.download_artifacts()
 
     @classmethod
@@ -651,7 +649,7 @@ def get_archive_name(cls, arch, os):
 
 
 class LibraryDownloader(BuildPyCommand):
-    def run(self):
+    def run(self) -> None:
         # The setuptools docs indicate the `editable_mode` attribute of the build_py command class
         # is set to True when the package is being installed in editable mode, which we need to know
         # for some extensions
@@ -699,7 +697,7 @@ def _strip_build_artifacts(self):
 
 class CleanLibraries(CleanCommand):
     @staticmethod
-    def remove_native_extensions():
+    def remove_native_extensions() -> None:
         """Remove native extensions and shared libraries installed by setup.py."""
         for pattern in ("*.so", "*.pyd", "*.dylib", "*.dll"):
             for path in DDTRACE_DIR.rglob(pattern):
@@ -711,20 +709,20 @@ def remove_native_extensions():
                         print(f"WARNING: could not remove {path}: {e}")
 
     @staticmethod
-    def remove_artifacts():
+    def remove_artifacts() -> None:
         shutil.rmtree(LIBDDWAF_DOWNLOAD_DIR, True)
         CleanLibraries.remove_native_extensions()
 
     @staticmethod
-    def remove_rust_targets():
+    def remove_rust_targets() -> None:
         """Remove all Rust target dirs (target, target3.9, target3.10, etc.)."""
         # rmtree is a superset of `cargo clean`; target* catches plain target and versioned
         for target_dir in NATIVE_CRATE.glob("target*"):
             if target_dir.is_dir():
                 shutil.rmtree(target_dir, True)
 
     @staticmethod
-    def remove_build_artifacts():
+    def remove_build_artifacts() -> None:
         """Remove egg-info, dist, .eggs, *.egg, and CMake FetchContent cache.
 
         The base distutils clean command does not remove these. They can cause
@@ -744,7 +742,7 @@ def remove_build_artifacts():
             shutil.rmtree(cmake_deps, True)
 
     @staticmethod
-    def remove_build_dir():
+    def remove_build_dir() -> None:
         """Remove the entire build/ tree for a clean slate.
 
         The base CleanCommand only removes specific subdirs (build_temp, build_lib, etc.)
@@ -754,7 +752,7 @@ def remove_build_dir():
         if build_dir.exists():
             shutil.rmtree(build_dir, True)
 
-    def run(self):
+    def run(self) -> None:
         CleanLibraries.remove_rust_targets()
         CleanLibraries.remove_artifacts()
         CleanLibraries.remove_build_dir()
@@ -837,7 +835,7 @@ def _absl_should_skip() -> bool:
 class CustomBuildExt(build_ext):
     INCREMENTAL = os.getenv("DD_CMAKE_INCREMENTAL_BUILD", "1").lower() in ("1", "yes", "on", "true")
 
-    def run(self):
+    def run(self) -> None:
         with _time_phase("build_rust"):
             self.build_rust()
 
@@ -855,7 +853,7 @@ def run(self):
         with _time_phase("build_extensions"):
             super().run()
 
-    def build_extensions(self):
+    def build_extensions(self) -> None:
         # Enable parallel extension builds by default.  All extensions are
         # independent at this point (Rust and libdd_wrapper are already built
         # in run()), so they can safely compile concurrently.  The user can
@@ -900,14 +898,14 @@ def build_rust(self):
             cargo_files = [NATIVE_CRATE / "Cargo.toml", NATIVE_CRATE / "Cargo.lock"]
 
             # Get all source files (including subdirectories)
-            source_files = []
+            source_files: list[Path] = []
             # Find all .rs files in the crate (including subdirectories)
             source_files.extend(NATIVE_CRATE.glob("**/*.rs"))
             # Add cargo files
             source_files.extend([f for f in cargo_files if f.exists()])
 
             # Check if any source file is newer than the library
-            newest_source_time = 0
+            newest_source_time: float = 0.0
             for src_file in source_files:
                 if src_file.exists():
                     newest_source_time = max(newest_source_time, src_file.stat().st_mtime)
@@ -970,13 +968,13 @@ def build_libdd_wrapper(self):
             wrapper_mtime = wrapper_library.stat().st_mtime
 
             # Check dd_wrapper source files
-            source_files = []
+            source_files: list[Path] = []
             source_files.extend(dd_wrapper_dir.glob("**/*.cpp"))
             source_files.extend(dd_wrapper_dir.glob("**/*.hpp"))
             source_files.extend([dd_wrapper_dir / "CMakeLists.txt"])
 
             # Check if any source file is newer than the wrapper library
-            newest_source_time = 0
+            newest_source_time: float = 0.0
             for src_file in source_files:
                 if src_file.exists():
                     newest_source_time = max(newest_source_time, src_file.stat().st_mtime)
@@ -999,7 +997,7 @@ def build_libdd_wrapper(self):
 
             install_args = [f"--config {COMPILE_MODE}"]
 
-            cmake_command = (Path(cmake.CMAKE_BIN_DIR) / "cmake").resolve()
+            cmake_command = (Path(cmake.CMAKE_BIN_DIR) / "cmake").resolve()  # type: ignore[attr-defined]
             subprocess.run([cmake_command, *cmake_args], cwd=cmake_build_dir, check=True)
             subprocess.run([cmake_command, "--build", ".", *build_args], cwd=cmake_build_dir, check=True)
             subprocess.run([cmake_command, "--install", ".", *install_args], cwd=cmake_build_dir, check=True)
@@ -1038,7 +1036,7 @@ def _build_shared_dep(self, dep: SharedDep) -> None:
         cmake_build_dir = Path(self.build_lib.replace("lib.", "cmake."), f"{dep.name}_build").resolve()
         cmake_build_dir.mkdir(parents=True, exist_ok=True)
 
-        cmake_command = (Path(cmake.CMAKE_BIN_DIR) / "cmake").resolve()
+        cmake_command = (Path(cmake.CMAKE_BIN_DIR) / "cmake").resolve()  # type: ignore[attr-defined]
 
         cmake_args = self._base_cmake_args() + [
             f"-S{dep.cmake_dir}",
@@ -1077,7 +1075,7 @@ def try_strip_symbols(so_file):
                     "WARNING: An error occurred while stripping the symbols from '{}', ignoring: {}".format(so_file, e)
                 )
 
-    def build_extension(self, ext):
+    def build_extension(self, ext: Extension) -> None:
         if isinstance(ext, CMakeExtension):
             try:
                 self.build_extension_cmake(ext)
@@ -1189,7 +1187,7 @@ def _get_common_cmake_args(self, source_dir, build_dir, output_dir, extension_na
         # Forward the install path of every successfully pre-built shared dep so
         # each consuming extension's CMakeLists.txt can use find_package() instead
         # of running its own FetchContent build.
-        built = getattr(self, "_built_shared_deps", set())
+        built: set[str] = getattr(self, "_built_shared_deps", set())
         for dep in SHARED_DEPS:
             if dep.name in built:
                 cmake_args += [f"-D{dep.cmake_var}={dep.install_dir}"]
@@ -1334,7 +1332,7 @@ def build_extension_cmake(self, ext: "CMakeExtension") -> None:
                 "-DCMAKE_CXX_FLAGS_%s=-O0" % ext.build_type.upper(),
             ]
         cmake_command = (
-            Path(cmake.CMAKE_BIN_DIR) / "cmake"
+            Path(cmake.CMAKE_BIN_DIR) / "cmake"  # type: ignore[attr-defined]
         ).resolve()  # explicitly use the cmake provided by the cmake package
         subprocess.run([cmake_command, *cmake_args], cwd=cmake_build_dir, check=True)
         subprocess.run([cmake_command, "--build", ".", *build_args], cwd=cmake_build_dir, check=True)
@@ -1391,7 +1389,7 @@ def dump_metadata(cls):
             for ext, elapsed_ns in sorted(cls.build_times.items(), key=lambda x: x[1], reverse=True):
                 elapsed_s = elapsed_ns / 1e9
                 ext_percent = (elapsed_ns / total_ns) * 100.0
-                f.write(f"\t{ext.name}: {elapsed_s:0.2f}s ({ext_percent:0.2f}%)\n")
+                f.write(f"\t{ext}: {elapsed_s:0.2f}s ({ext_percent:0.2f}%)\n")
 
             if cls.shared_dep_times:
                 f.write("Shared dependency build times:\n")
@@ -1447,25 +1445,29 @@ def _time_phase(name: str):
 
 if DebugMetadata.enabled:
     DebugMetadata.start_ns = time.time_ns()
-    CustomBuildExt.build_extension = debug_build_extension(CustomBuildExt.build_extension)
-    CustomBuildExt._build_shared_dep = debug_build_shared_dep(CustomBuildExt._build_shared_dep)
+    CustomBuildExt.build_extension = (  # type: ignore[method-assign]
+        debug_build_extension(CustomBuildExt.build_extension)
+    )
+    CustomBuildExt._build_shared_dep = (  # type: ignore[method-assign]
+        debug_build_shared_dep(CustomBuildExt._build_shared_dep)
+    )
     build_rust.build_extension = debug_build_extension(CustomBuildRust.build_extension)
     atexit.register(DebugMetadata.dump_metadata)
 
 
 class CMakeExtension(Extension):
     def __init__(
         self,
-        name,
-        source_dir=Path.cwd(),
-        extra_source_dirs=[],
-        cmake_args=[],
-        build_args=[],
-        install_args=[],
-        build_type=None,
-        optional=True,  # By default, extensions are optional
-        dependencies=[],
-    ):
+        name: str,
+        source_dir: Path = Path.cwd(),
+        extra_source_dirs: list[Path] = [],
+        cmake_args: list[str] = [],
+        build_args: list[str] = [],
+        install_args: list[str] = [],
+        build_type: t.Optional[str] = None,
+        optional: bool = True,  # By default, extensions are optional
+        dependencies: list[Path] = [],
+    ) -> None:
         super().__init__(name, sources=[])
         self.source_dir = source_dir
         self.extra_source_dirs = extra_source_dirs  # extra source dirs to include when computing extension hash
@@ -1488,7 +1490,7 @@ def get_sources(self) -> list[Path]:
         def is_valid_source(src: Path) -> bool:
             return (
                 src.is_file()
-                and src.suffix
+                and bool(src.suffix)
                 # Exclude compiled/generated artifacts that are not real sources:
                 # .so/.dylib/.dll/.pyd — compiled native extensions (from co-located Cython exts)
                 # .c — Cython-generated C files (present in shared source directories)
@@ -1571,7 +1573,7 @@ def get_exts_for(name):
 
 
 if not IS_PYSTON:
-    ext_modules: list[t.Union[Extension, Cython.Distutils.Extension, RustExtension]] = [
+    ext_modules: list[t.Union[Extension, CythonExtension, RustExtension]] = [
         Extension(
             "ddtrace.internal._threads",
             sources=["ddtrace/internal/_threads.cpp"],
@@ -1654,7 +1656,7 @@ def get_exts_for(name):
 if os.getenv("DD_CYTHONIZE", "1").lower() in ("1", "yes", "on", "true"):
     with _time_phase("cythonize"):
         _cython_sources = [
-            Cython.Distutils.Extension(
+            CythonExtension(
                 "ddtrace.internal._tagset",
                 sources=["ddtrace/internal/_tagset.pyx"],
                 language="c",
@@ -1675,32 +1677,32 @@ def get_exts_for(name):
 
         if sys.version_info < (3, 15):
             _cython_sources += [
-                Cython.Distutils.Extension(
+                CythonExtension(
                     "ddtrace.profiling._threading",
                     sources=["ddtrace/profiling/_threading.pyx"],
                     language="c",
                 ),
-                Cython.Distutils.Extension(
+                CythonExtension(
                     "ddtrace.profiling.collector._task",
                     sources=["ddtrace/profiling/collector/_task.pyx"],
                     language="c",
                 ),
-                Cython.Distutils.Extension(
+                CythonExtension(
                     "ddtrace.profiling.collector._exception",
                     sources=["ddtrace/profiling/collector/_exception.pyx"],
                     language="c",
                 ),
-                Cython.Distutils.Extension(
+                CythonExtension(
                     "ddtrace.profiling.collector._fast_poisson",
                     sources=["ddtrace/profiling/collector/_fast_poisson.pyx"],
                     language="c",
                 ),
-                Cython.Distutils.Extension(
+                CythonExtension(
                     "ddtrace.profiling.collector._sampler",
                     sources=["ddtrace/profiling/collector/_sampler.pyx"],
                     language="c",
                 ),
-                Cython.Distutils.Extension(
+                CythonExtension(
                     "ddtrace.profiling.collector._lock",
                     sources=["ddtrace/profiling/collector/_lock.pyx"],
                     language="c",