relax accepted types for run_work_space command

diff --git a/mkosi/backend.py b/mkosi/backend.py
index 57b37a5887d6ee2ecabc563b1912eb8ae99a9628..5cbd8e1671f8703279a3b37a736ac1181e54b4a6 100644 (file)
--- a/mkosi/backend.py
+++ b/mkosi/backend.py
@@ -27,6 +27,7 @@ from typing import (
     Dict,
     Iterator,
     List,
+    Mapping,
     NoReturn,
     Optional,
     Sequence,
@@ -606,7 +607,7 @@ def run_workspace_command(
     root: Path,
     cmd: Sequence[PathString],
     network: bool = False,
-    env: Optional[Dict[str, str]] = None,
+    env: Optional[Mapping[str, str]] = None,
     nspawn_params: Optional[List[str]] = None,
     capture_stdout: bool = False,
 ) -> Optional[str]: