Index: tox-4.11.1/src/tox/pytest.py
===================================================================
--- tox-4.11.1.orig/src/tox/pytest.py
+++ tox-4.11.1/src/tox/pytest.py
@@ -16,7 +16,10 @@ from typing import TYPE_CHECKING, Any, C
 
 import pytest
 from _pytest.fixtures import SubRequest
-from devpi_process import IndexServer
+try:
+    from devpi_process import IndexServer
+except ImportError:
+    IndexServer = None
 from virtualenv.info import fs_supports_symlink
 
 import tox.run
Index: tox-4.11.1/tests/test_provision.py
===================================================================
--- tox-4.11.1.orig/tests/test_provision.py
+++ tox-4.11.1/tests/test_provision.py
@@ -16,7 +16,10 @@ from filelock import FileLock
 from packaging.requirements import Requirement
 
 if TYPE_CHECKING:
-    from devpi_process import Index, IndexServer
+    try:
+        from devpi_process import Index, IndexServer
+    except ImportError:
+        Index, IndexServer = None, None
 
     from tox.pytest import MonkeyPatch, TempPathFactory, ToxProjectCreator