sphinxarg.ext generates generic sub-headings ("Named arguments", "Positional arguments", "Sub-commands", "General options", ...) for every argparse command and tool. These repeat across many files and trigger large numbers of autosectionlabel duplicate-label warnings.
Two-pronged fix:
* `autosectionlabel_maxdepth = 3` eliminates the depth-4+ warnings (sub-headings inside each individual command block). * `suppress_warnings` per file silences the residual depth-3 collisions ("serial reader", "decode_hex", "sub-commands", ...) that still appear across tool documentation files.
Cross-references into these generic argparse-generated sections are not a supported use-case, so suppressing the warnings is appropriate.
