Drop dependency on distutils

pybind_interface/Dockerfile

@@ -2,7 +2,7 @@
 FROM qsim
 
 # Install additional requirements
-RUN apt-get install -y python3-dev python3-pybind11 python3-pip python3-venv
+RUN apt-get install -y python3-dev python3-pybind11 python3-pip python3-venv python3-packaging
 
 # Create venv to avoid collision between system packages (e.g. numpy) and Cirq's deps.
 RUN python3 -m venv test_env

setup.py

@@ -7,7 +7,7 @@
 
 from setuptools import setup, Extension
 from setuptools.command.build_ext import build_ext
-from distutils.version import LooseVersion
+from packaging.version import parse
 
 
 class CMakeExtension(Extension):
@@ -27,7 +27,7 @@ def run(self):
             )
 
         if platform.system() == "Windows":
-            cmake_version = LooseVersion(
+            cmake_version = parse(
                 re.search(r"version\s*([\d.]+)", out.decode()).group(1)
             )
             if cmake_version < "3.1.0":