TMP / pre-commit.py: make parallelism a str

tools/pre-commit.py

@@ -186,7 +186,9 @@ def unformat_project(indexed):
 def build_project():
     """Build project with cmake."""
     print('Building project')
-    build_log = invoke(*cmake, '--build', build_root, '--parallel', parallelism,
+    build_log = invoke(*cmake,
+                       '--build', build_root,
+                       '--parallel', str(parallelism),
                        result_when_dry=CLANG_TIDY_CHECK_MARKER,
                        quiet=False)