handle older sphinx

Author: blink1073

tests/test_execute.py

@@ -13,6 +13,11 @@
 from sphinx.addnodes import download_reference
 from sphinx.errors import ExtensionError
 from sphinx.testing.util import SphinxTestApp, assert_node
+try:
+    from sphinx.testing.util import path
+except ImportError:
+    path = None
+
 
 from jupyter_sphinx.ast import (
     JupyterCellNode,
@@ -47,6 +52,8 @@ def doctree(
         (src_dir / "index.rst").write_text(source, encoding="utf8")
 
         warnings = StringIO()
+        if path is not None:
+            src_dir = path(src_dir.as_posix())
         app = SphinxTestApp(
             srcdir=src_dir,
             status=StringIO(),