diff --git a/setuptools_git_versioning.py b/setuptools_git_versioning.py
index ab4ff00..19d7965 100644
--- a/setuptools_git_versioning.py
+++ b/setuptools_git_versioning.py
@@ -15,6 +15,11 @@
 from pprint import pformat
 from typing import TYPE_CHECKING, Any, Callable
 
+# because we use distutils in this file, we need to ensure that setuptools is
+# imported first so that it can do monkey patching. this is not always already
+# done for us, for example, when running this in a test or as a module
+import setuptools  # noqa: F401
+
 if TYPE_CHECKING:
     # avoid importing 'packaging' because setuptools-git-versioning can be installed using sdist
     # where 'packaging' is not installed yet
diff --git a/tests/lib/util.py b/tests/lib/util.py
index 3706a8b..ab218cf 100644
--- a/tests/lib/util.py
+++ b/tests/lib/util.py
@@ -30,6 +30,13 @@ def rand_sha() -> str:
 
 def execute(cwd: str | os.PathLike, cmd: str, **kwargs) -> str:
     log.info(f"Executing '{cmd}' at '{cwd}'")
+
+    if "env" in kwargs:
+        kwargs["env"]["PATH"] = os.environ["PATH"]
+        pythonpath = os.getenv("PYTHONPATH", None)
+        if pythonpath:
+            kwargs["env"]["PYTHONPATH"] = pythonpath
+
     return subprocess.check_output(cmd, cwd=cwd, shell=True, universal_newlines=True, **kwargs)  # nosec