* Copy uv `-c`/`-r` paths to a space-free temp dir on macOS/Linux
uv 0.11.x truncates a constraints/requirements path passed via `-c`/`-r`
at the first space, so `unsloth studio` setup from a repo cloned under a
path containing a space (e.g. `/Users/me/Open Source/unsloth`) fails with:
error: File not found: `/Users/me/Open`
_uv_safe_path() already worked around this on Windows via the 8.3 short
path but returned the space-containing path unchanged on macOS/Linux,
which have no 8.3 equivalent. Extend it to copy the (small, flat)
constraints/requirements file into a space-free temp dir and hand uv the
copy; the temp dirs are removed at process exit. Falls back to the
original path on any error, so it is never worse than before.
Refs unslothai/unsloth#6503
* Route UV_OVERRIDE through _uv_safe_path and fix temp-dir leak (#6503)
The -c/-r fix did not cover UV_OVERRIDE, which uv also truncates at the first
space. On Apple Silicon the overrides file is handed to uv via UV_OVERRIDE at
install time (install_python_stack.py) and during the MLX self-heal
(utils.mlx_repair), so a repo under a path containing a space still broke every
uv call there. Move _uv_safe_path into backend.utils.uv_path_safety so both
sites share it, and route UV_OVERRIDE through it.
Also stop leaking the temp dir when shutil.copyfile fails after mkdtemp, and add
tests for the UV_OVERRIDE channel, the TMPDIR-with-space fallback, the atexit
cleanup, and the no-leak path.
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Co-authored-by: danielhanchen <danielhanchen@gmail.com>
