fix math-python pyproject so it is installable

[cdreetz]

Description

Add [tool.hatch.build] to math-python pyproject. Without it running vf-eval math-python results in error:

christian@math_python$ uv run vf-eval math-python -n 1 -r 1
warning: The `extra-build-dependencies` option is experimental and may change without warning. Pass `--preview-features extra-build-dependencies` to disable this warning.
      Built math-python @ file:///Users/christian/dev/my-prime/my-verifiers/docker-sandbox/verifiers/environments/math_python
Uninstalled 1 package in 2ms
Installed 1 package in 1ms
2025-12-13 14:53:56 - verifiers.utils.eval_utils - WARNING - No local endpoint registry found at ./configs/endpoints.py. Please specify the model name (-m), API host base URL (-b), and API key variable name (-k). Error details: endpoints.py not found at configs/endpoints.py
2025-12-13 14:53:56 - verifiers.utils.env_utils - INFO - Loading environment: math-python
2025-12-13 14:53:56 - verifiers.utils.env_utils - ERROR - Failed to import environment module math_python for env_id math-python: No module named 'math_python'
Traceback (most recent call last):
  File "/Users/christian/dev/verifiers/verifiers/utils/env_utils.py", line 15, in load_environment
    module = importlib.import_module(module_name)
  File "/opt/homebrew/Cellar/python@3.13/3.13.3/Frameworks/Python.framework/Versions/3.13/lib/python3.13/importlib/__init__.py", line 88, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1324, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'math_python'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/christian/.local/bin/vf-eval", line 10, in <module>
    sys.exit(main())
             ~~~~^^
  File "/Users/christian/dev/verifiers/verifiers/scripts/eval.py", line 239, in main
    asyncio.run(run_evaluation(eval_config))
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/python@3.13/3.13.3/Frameworks/Python.framework/Versions/3.13/lib/python3.13/asyncio/runners.py", line 195, in run
    return runner.run(main)
           ~~~~~~~~~~^^^^^^
  File "/opt/homebrew/Cellar/python@3.13/3.13.3/Frameworks/Python.framework/Versions/3.13/lib/python3.13/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "/opt/homebrew/Cellar/python@3.13/3.13.3/Frameworks/Python.framework/Versions/3.13/lib/python3.13/asyncio/base_events.py", line 719, in run_until_complete
    return future.result()
           ~~~~~~~~~~~~~^^
  File "/Users/christian/dev/verifiers/verifiers/utils/eval_utils.py", line 110, in run_evaluation
    vf_env = vf.load_environment(env_id=config.env_id, **config.env_args)
  File "/Users/christian/dev/verifiers/verifiers/utils/env_utils.py", line 81, in load_environment
    raise ValueError(
        f"Could not import '{env_id}' environment. Ensure the package for the '{env_id}' environment is installed."
    ) from e
ValueError: Could not import 'math-python' environment. Ensure the package for the 'math-python' environment is installed.

But after:

christian@math_python$ uv run vf-eval math-python -n 1 -r 1
warning: The `extra-build-dependencies` option is experimental and may change without warning. Pass `--preview-features extra-build-dependencies` to disable this warning.
/Users/christian/dev/my-prime/my-verifiers/docker-sandbox/verifiers/environments/math_python/.venv/lib/python3.14/site-packages/multiprocess/connection.py:335: SyntaxWarning: 'return' in a 'finally' block
  return f
/Users/christian/dev/my-prime/my-verifiers/docker-sandbox/verifiers/environments/math_python/.venv/lib/python3.14/site-packages/multiprocess/connection.py:337: SyntaxWarning: 'return' in a 'finally' block
  return self._get_more_data(ov, maxsize)
2025-12-13 14:54:36 - verifiers.utils.eval_utils - WARNING - No local endpoint registry found at ./configs/endpoints.py. Please specify the model name (-m), API host base URL (-b), and API key variable name (-k). Error details: endpoints.py not found at configs/endpoints.py
2025-12-13 14:54:36 - verifiers.utils.env_utils - INFO - Loading environment: math-python
2025-12-13 14:54:36 - verifiers.utils.env_utils - INFO - Using default args: sandbox_memory_gb=2, dataset_split='train', sandbox_cpu_cores=1, num_train_examples=-1, dataset_name='math', max_startup_wait_seconds=30, pip_install_packages='numpy sympy scipy', sandbox_timeout_per_command_seconds=30, sandbox_timeout_minutes=60, max_turns=100, sandbox_gpu_count=0, sandbox_disk_size_gb=5
2025-12-13 14:54:39 - verifiers.rubrics.RubricGroup - INFO - Initialized RubricGroup with 2 rubrics
2025-12-13 14:54:39 - verifiers.utils.env_utils - INFO - Successfully loaded environment 'math-python'
2025-12-13 14:54:39 - verifiers.utils.eval_utils - INFO - Starting evaluation with model: gpt-4.1-mini
2025-12-13 14:54:39 - verifiers.utils.eval_utils - INFO - Configuration: num_examples=1, rollouts_per_example=1, max_concurrent=32
2025-12-13 14:54:39 - verifiers.envs.PythonEnv - INFO - eval_dataset is not set, falling back to train dataset
Processing 1 groups (1 total rollouts):   0%|                                                                     | 0/1 [00:00<?, ?it/s]

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Test improvement

Testing

• All existing tests pass when running uv run pytest locally.
• New tests have been added to cover the changes

Checklist

• My code follows the style guidelines of this project as outlined in AGENTS.md
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published

Additional Notes

[mikasenghaas]

hm, it's installable for me with uv pip install -e environments/math_python

[willccbb]

@mikasenghaas we should always have the hatch setup to ensure env hub installs + vf-install work properly