Allow configurable generated-files builder timeout

scripts/check_generated_files_current.py

@@ -65,6 +65,9 @@
 after CI's own build_explainers.py/generate_og_images.py steps to be
 meaningful, though CI still runs it there too.
 
+The regeneration timeout can be configured with the optional
+FAIRCODE_BUILD_TIMEOUT environment variable (in seconds). Invalid or
+non-positive values fall back to the default of 600 seconds.
 Run locally:  python3 scripts/check_generated_files_current.py
 Exit code:    0 = everything current, 1 = something is genuinely stale.
 """
@@ -76,9 +79,11 @@
 import subprocess
 import sys
 import tempfile
+import os
 from contextlib import ExitStack
 from pathlib import Path
 
+
 from PIL import Image
 
 ROOT = Path(__file__).resolve().parent.parent
@@ -128,7 +133,19 @@ def _expected_og_slugs():
     return ["home", "profiler"] + [entry["slug"] for entry in entries]
 
 
-BUILD_TIMEOUT = 600.0      # seconds for each of the three regeneration steps (#1292)
+def _get_build_timeout() -> float:
+    """Returns the build timeout from FAIRCODE_BUILD_TIMEOUT, or 600 seconds."""
+    try:
+        timeout = float(os.environ.get("FAIRCODE_BUILD_TIMEOUT", "600"))
+        if timeout > 0:
+            return timeout
+    except ValueError:
+        pass
+
+    return 600.0
+
+
+BUILD_TIMEOUT = _get_build_timeout()   # seconds for each of the three regeneration steps (#1292)
 
 
 class BuilderTimeout(RuntimeError):

tests/test_check_generated_files_current.py

@@ -443,3 +443,26 @@ def test_builder_names_say_which_step_stalled():
     assert script._builder_name(["python", "scripts/build_explainers.py"]) == "scripts/build_explainers.py"
     assert "MCP results mirror" in script._builder_name(["python", "-c", "from scripts.freeze_paper_results import x"])
     assert str(script.BuilderTimeout("scripts/x.py", 5)) == "scripts/x.py did not finish within 5 s"
+
+def test_build_timeout_uses_environment_variable(monkeypatch):
+    script = _script()
+    monkeypatch.setenv("FAIRCODE_BUILD_TIMEOUT", "120")
+
+    assert script._get_build_timeout() == 120.0
+
+
+def test_build_timeout_defaults_to_600(monkeypatch):
+    script = _script()
+    monkeypatch.delenv("FAIRCODE_BUILD_TIMEOUT", raising=False)
+
+    assert script._get_build_timeout() == 600.0
+
+
+@pytest.mark.parametrize("value", ["abc", "", "0", "-10"])
+def test_build_timeout_invalid_values_fall_back_to_600(
+    monkeypatch, value
+):
+    script = _script()
+    monkeypatch.setenv("FAIRCODE_BUILD_TIMEOUT", value)
+
+    assert script._get_build_timeout() == 600.0