Dropping support for old bash versions

[scop]

I'd like to look into dropping support for old bash versions soon after we get 2.17.0 out.

Ref: https://github.com/scop/bash-completion/wiki/Minimum-bash-versions

To me it currently looks like as if dropping bash < 5.1 support would be the way to go. The only family of distros in "non-extended maintenance mode" affected by this would be RHEL 8 and friends as far as I can tell. I think those and the ones in extended maintenance are adequately served by current bash completion versions.

Per semver this would come with a bash-completion major version bump.

What this would entail would be code cleanups we can do within the new supported version range, and adjusting CI etc for testing only with those versions.

Yays/nays?

[akinomyoga]

dropping bash < 5.1

What kind of code cleanups can we expect by lifting the version requirement specifically to 5.1? The wiki page lists cleanups for 4.3 and 4.4, but it doesn't list possible cleanups for 5.0 and 5.1. If there are no significant cleanups with 5.0 and 5.1, we can still support 4.4 with essentially the same codebase for 5.1.

Also, in my experience with my repositories, there are still people using Ubuntu 16.04 LTS (in larger systems that are harder to replace).

[scop]

Like the wiki page says, cleanups for 5.0 and 5.1 (note BTW that I'm not proposing dropping 5.1) are TBD. I do expect there to be various opportunities though.

Re things as old as Ubuntu 16.04, as said, I think those are adequately served by existing bash completion versions. Surely we have various bugs lurking here and there, but users of such systems are less likely to need feature updates or ones serving updated versions of tools we have completions for.