fix(cli): resolve subpackage register paths before deduplication

[Anai-Guo]

Problem

Closes #2417.

On RHEL / CentOS-derived distributions lib64 is a symlink to lib, so both site-packages directories end up in commands_register_spec.submodule_search_locations:

/home/user/.venv/lib64/python3.12/site-packages
/home/user/.venv/lib/python3.12/site-packages

register_optimum_cli_subcommands deduplicates that list with a plain set(...), which compares the raw path strings. Since the strings differ, the same register module is imported twice — once via lib, once via lib64. The duplicate REGISTER_COMMANDS entries then try to register identical subparsers and any optimum-cli invocation that pulls in a subpackage (e.g. optimum-cli export onnx --help) blows up with:

argparse.ArgumentError: argument {onnx}: conflicting subparser: onnx

Ubuntu / Debian only ship lib, so the bug never surfaced there. The reporter narrowed it down on CentOS Stream 10; it also reproduces on Fedora, RHEL 8/9 and any virtualenv created on those distros.

Fix

Resolve each candidate path with Path.resolve() before building the deduplication set. Symlinked siblings collapse to one canonical absolute path, so the registration loop runs exactly once per real directory.

register_paths = {
    Path(register_path).resolve()
    for register_path in commands_register_spec.submodule_search_locations
}
for register_path in register_paths:
    ...

The rest of the loop is unchanged — register_path was already being wrapped in Path(...) on the first line of the body, so the resolved Path object is a drop-in replacement.

Why this is safe

• No behavior change on Ubuntu / Debian / Windows / macOS — submodule_search_locations contains a single entry, Path.resolve() returns it unchanged.
• No new dependency — pathlib.Path is already imported at the top of the module.
• No double-iteration — the comprehension materializes the set before the loop begins, matching the previous semantics.
• commands_register_spec.submodule_search_locations is None short-circuit is preserved (lines above the change).

Reproduction (matches the issue)

# CentOS Stream 10 / Fedora / RHEL 8+
python3 -m venv .venv && source .venv/bin/activate
pip install optimum optimum-onnx
python -c "import sys; [print(p) for p in sys.path if 'site-packages' in p]"
# -> shows both lib and lib64 paths
optimum-cli export onnx --help
# Before: argparse.ArgumentError: conflicting subparser: onnx
# After:  prints the help text

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🤖 Generated with Claude Code

[Anai-Guo]

Added a hermetic regression test (tests/cli/test_cli.py::test_symlinked_register_paths_are_deduplicated) that reproduces the double-import: it stubs submodule_search_locations with a directory plus a symlink resolving to the same path and asserts the register module is imported exactly once. It fails on the previous set(...) dedup and passes with the Path(...).resolve() fix. No production code changed.

🤖 Generated with Claude Code