Fix environments not being reused due to wrong Python lookup (#428)

nox/virtualenv.py

@@ -336,9 +336,11 @@ def _check_reused_environment_interpreter(self) -> bool:
         """Check if reused environment interpreter is the same."""
         program = "import sys; print(getattr(sys, 'real_prefix', sys.base_prefix))"
         original = nox.command.run(
-            [self._resolved_interpreter, "-c", program], silent=True
+            [self._resolved_interpreter, "-c", program], silent=True, log=False
+        )
+        created = nox.command.run(
+            ["python", "-c", program], silent=True, log=False, paths=self.bin_paths
         )
-        created = nox.command.run(["python", "-c", program], silent=True)
         return original == created
 
     @property

tests/test_virtualenv.py

@@ -410,20 +410,17 @@ def test_create_reuse_venv_environment(make_one):
     venv, location = make_one(reuse_existing=True, venv=True)
     venv.create()
 
-    # Use a spurious occurrence of "virtualenv" in the pyvenv.cfg.
-    pyvenv_cfg = """\
-    home = /opt/virtualenv/bin
-    include-system-site-packages = false
-    version = 3.9.6
-    """
-    location.join("pyvenv.cfg").write(dedent(pyvenv_cfg))
+    # Place a spurious occurrence of "virtualenv" in the pyvenv.cfg.
+    pyvenv_cfg = location.join("pyvenv.cfg")
+    pyvenv_cfg.write(pyvenv_cfg.read() + "bogus = virtualenv\n")
 
     reused = not venv.create()
 
     # The environment should be detected as venv-style and reused.
     assert reused
 
 
+@pytest.mark.skipif(IS_WINDOWS, reason="Avoid 'No pyvenv.cfg file' error on Windows.")
 def test_create_reuse_oldstyle_virtualenv_environment(make_one):
     venv, location = make_one(reuse_existing=True)
     venv.create()