release-fast and release-small profiles and a page on packaging in the docs.

[tertsdiepraam]

Inspired by #4436 and #747.

In the comments of #4436, I did an exploration of the binary size by trying different settings in cargo. The conclusion was that we can get the binary size down by a lot (even smaller than GNU), but that this will make bug reports less useful. Therefore, we should leave the exact configuration up to package maintainers. To document that, I've written a page on packaging this project in the docs. This page explains the best practices for the package name (since we had some issues there) and how to configure the package.

Additionally, to quickly see what our best performance and smallest binary size is, I've created the release-fast and release-small profiles in addition to the standard release profile. The release profile also has lto enabled, because that (probably) gives a performance boost and reduces the binary quite a bit, without removing any debug info, but compilation takes a bit slower. (I haven't benchmarked the performance and compile time though)

The change in stdbuf is because it was using the PROFILE env variable, which can only be release or debug and does not become, for example, release-fast and was therefore failing to compile.

@sylvestre, since you're packaging expert; is there anything else we should mention on the packaging page?

[tertsdiepraam]

Btw, we might need to advertise these alternative profiles a bit more after this. It would be nice to not have people complain about binary size for once when this project makes the rounds again 😄

[tertsdiepraam]

Oh great, I now remember why stdbuf was using that variable in the first place: #2843. I'll look into a solution tomorrow.

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/tail-2/inotify-dir-recreate. tests/tail-2/inotify-dir-recreate is passing on 'main'. Maybe you have to rebase?

[sylvestre]

I think it would be nice to test both of them in the CI, don't you think ? :)

[tertsdiepraam]

Yes, I'll add that too!

[tertsdiepraam]

On second thought, maybe it's not that helpful to add in the CI? Apart from the anomaly with stdbuf, the profile should have very little effect on whether or not it compiles.

[sylvestre]

ok, you are probably correct :)

[tertsdiepraam]

@sylvestre I think this causes problems after all. Lot's of builds failing because of stdbuf. We should probably revert this.

[sylvestre]

@tertsdiepraam it improves it significantly:
https://raw.githubusercontent.com/uutils/coreutils-tracking/main/size-results.png
;)

[tertsdiepraam]

Nice! And that's just the lto change too.

On second thought, maybe it's not that helpful to add in the CI? Apart from the anomaly with stdbuf, the profile should have very little effect on whether or not it compiles.

I'm not so sure about this anymore, it would be interesting to add it to the CI just for tracking the size.