cat: replace nix with rustix

[oech3]

depends on #11566
split #11548

[codspeed-hq]

Merging this PR will not alter performance

✅ 304 untouched benchmarks
⏩ 46 skipped benchmarks¹

---

_{Comparing oech3:cat-r (5a9b8c6) with main (3b2a09c)²}

Footnotes

1. 46 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on main (04b1585) during the generation of this report, so 3b2a09c was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/date/date-locale-hour (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/tail/follow-name (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/inotify-dir-recreate (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/unexpand/bounded-memory is now passing!

[oech3]

macOS's rustix does not have raw backend helping binary size. Also we need to remove nix from uucore since cat deps on it.

[oech3]

Also it is known that raw backend is sometimes bad perf compared with nix. So we might switch to use-libc backend and revert binary size. Even so, we reduce 1 dep needed to build.

[xtqqczze]

is CatError::Rustix used?

[oech3]

I don't know. But clippy did not say anything about unused import.

[xtqqczze]

Clippy doesn't warn about unused enum variants.

[xtqqczze]

is there a difference in Linux binary size, I'm just interested...?

[oech3]

I did git reset --hard
rustix (raw) 1201576
nix 1219232
rusitx (use-libc) 1202512

[oech3]

Did you strip binaries?

[xtqqczze]

Did you strip binaries?

No, these are the stripped sizes:

--profile release-small (aarch64-apple-darwin): 817760 -> 817776

[xtqqczze]

I did git reset --hard rustix (raw) 1201576 nix 1219232 rusitx (use-libc) 1202512

So rustix (especially raw) may be a good size improvement.