Account for possibility bdist_wheel is not installed

Author: abravalheri

setuptools_rust/setuptools_ext.py

@@ -4,7 +4,7 @@
 import sysconfig
 import logging
 
-from typing import List, Set, Tuple, Type, TypeVar, cast
+from typing import List, Optional, Set, Tuple, Type, TypeVar, cast
 from functools import partial
 
 from setuptools.command.build_ext import build_ext
@@ -163,14 +163,18 @@ def run(self) -> None:
                 build_rust.inplace = self.inplace
                 build_rust.target = self.target
                 build_rust.verbose = self.verbose
-
-                bdist_wheel = self.distribution.get_command_obj("bdist_wheel")
-                plat_name = bdist_wheel.plat_name or self.plat_name
-                build_rust.plat_name = plat_name
+                build_rust.plat_name = self._get_wheel_plat_name() or self.plat_name
                 build_rust.run()
 
             build_ext_base_class.run(self)
 
+        def _get_wheel_plat_name(self) -> Optional[str]:
+            try:
+                cmd = self.distribution.get_command_obj("bdist_wheel")
+                return cast(Optional[str], cmd.plat_name)
+            except Exception:  # unlikely scenario: `wheel` not installed
+                return None
+
     dist.cmdclass["build_ext"] = build_ext_rust_extension
 
     clean_base_class = dist.cmdclass.get("clean")