Restore Windows compatibility in doctest.

conftest.py

@@ -1,3 +1,6 @@
+import ntpath
+import posixpath
+import pprint
 import textwrap
 
 import jaraco.path
@@ -51,3 +54,18 @@ class Paths:
 @pytest.fixture(params=['persist', 'ephemeral'])
 def run_mode(monkeypatch, request):
     monkeypatch.setenv('PIP_RUN_MODE', request.param)
+
+
+@pytest.fixture
+def doctest_namespace():
+    def norm_path(path):
+        return (
+            path.replace(ntpath.sep, posixpath.sep)
+            .replace(ntpath.pathsep, posixpath.sep)
+            .replace('//', '/')
+        )
+
+    def norm_env_paths(env):
+        return {key: norm_path(value) for key, value in env.items()}
+
+    return dict(locals(), pprint=pprint.pprint)

pip_run/launch.py

@@ -51,9 +51,9 @@ def _build_env(target, *, orig=os.environ):
     """
     Prepend target to PYTHONPATH and add $target/bin to PATH.
 
-    >>> import pprint
     >>> orig = dict(PYTHONPATH='/orig', PATH='/orig')
-    >>> pprint.pprint(_build_env(pathlib.Path('/tmp/pip-run/target'), orig=orig))
+    >>> env = _build_env(pathlib.Path('/tmp/pip-run/target'), orig=orig)
+    >>> pprint(norm_env_paths(env))
     {'PATH': '/tmp/pip-run/target/bin:/orig',
      'PYTHONPATH': '/tmp/pip-run/target:/orig'}
     """