Fix tree_map_with_path for namedtuples - #3674

Added one more regression in chrismicah/codex/fix-tree-map-with-path-namedtuple@243b1c94 covering tree_map_with_path over a NamedTuple with a matching rest tree, so the fix is not only single-tree reconstruction.

Verification:

• Passed a Metal-free pure-Python import of python/mlx/utils.py exercising NamedTuple single-tree and rest-tree cases.
• python python/tests/test_tree.py cannot run in this headless environment because installed MLX fails during import with [metal::load_device] No Metal device available before reaching test_tree.

Your text is not very readable.

Thanks, agreed. I cleaned up the PR description so it renders as normal Markdown sections instead of escaped newline text, and kept the test notes concise.

• python -m pytest python/tests/test_tree.py -q blocked before collection in this headless session: RuntimeError: [metal::load_device] No Metal device available

You can disable metal backend when building.

Thanks, that worked. I rebuilt this PR branch with Metal disabled and reran the requested test successfully.

Commands/results:

CMAKE_ARGS="-DMLX_BUILD_METAL=OFF" CMAKE_BUILD_PARALLEL_LEVEL=4 \
  /Users/chris.s/.pyenv/versions/3.11.7/bin/python -m pip install -e .
# Successfully installed mlx-0.32.0.dev20260614+19489666

/Users/chris.s/.pyenv/versions/3.11.7/bin/python -m pytest python/tests/test_tree.py -q
# 4 passed in 0.25s

/Users/chris.s/.pyenv/versions/3.11.7/bin/python -m pytest python/tests/test_utils_pyonly.py -q
# 1 passed in 0.03s

I also confirmed the rebuilt extension is the local PR build and Metal is disabled:

mlx /Users/chris.s/conductor/workspaces/ml-ide/caracas/.codex_tmp/mlx-pr3674/python/mlx/core.cpython-311-darwin.so
metal available False

test_utils_pyonly.py can be removed now?

Removed it. The PR diff is now only:

• python/mlx/utils.py
• python/tests/test_tree.py

Re-ran after the cleanup:

/Users/chris.s/.pyenv/versions/3.11.7/bin/python -m pytest python/tests/test_tree.py -q
# 4 passed in 0.30s