Add pre-commit hook to check for uncommitted regenerated spec files.

Skip hook when calling pre-commit in generate script to avoid recursion.

.pre-commit-config.yaml

@@ -1,5 +1,13 @@
 exclude: (\.git/|\.tox/|\.venv/|le_utils\.egg-info)
 repos:
+-   repo: local
+    hooks:
+    -   id: rebuild-from-specs
+        name: Regenerate files
+        description: Regenerates files when specs or version has changed
+        entry: make build
+        language: system
+        files: (spec/.*\.json|setup\.py)$
 -   repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v2.0.0
     hooks:

scripts/generate_from_specs.py

@@ -307,4 +307,7 @@ def set_package_json_version():
 
     output_files += set_package_json_version()
 
-    subprocess.call(["pre-commit", "run", "--files"] + output_files)
+    env = os.environ.copy()
+    env["SKIP"] = "rebuild-from-specs"
+
+    subprocess.call(["pre-commit", "run", "--files"] + output_files, env=env)