Re: [RFC/PATCH] perl: bump the required Perl version to 5.10.0 from 5.8.0

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

On Sat, Dec 23 2017, brian m. carlson jotted:

> On Sat, Dec 23, 2017 at 05:44:00PM +0000, Ævar Arnfjörð Bjarmason wrote:
>> The reason to do this is to be able to use features released with perl
>> in the last decade, 5.10 was a major feature release including things
>> like new regex features, state variables, the defined-or operator
>> etc.[3]
>>
>> I expect this to be more controversial as since the 5.8 release stayed
>> along for longer in various distributions, e.g. it's the version
>> shipped with RHEL 5, replaced by 5.10 in RHEL 6 released in late 2010,
>> similarly the first Debian release to include 5.10 was 5.0 (Lenny)
>> released in early 2009. The release history for other distributions
>> can be seen on CPAN's "Perl Binaries" page[3].
>
> This is fine by me.  As far as I know, 5.10.1 is the oldest version of
> Perl still security-supported by a major Linux vendor.
>
> Feature-wise, the release I'd much rather see is 5.14, since it provides
> the r modifier to s/// and tr/// and undef-transparent length, but that
> simply won't be possible until RHEL 6 and CentOS 6 go EOL.  Upgrading to
> 5.10 is better than nothing, and it does get us defined-or, which is one
> of the only 5.10 features I ever see used.

Indeed, but as you point out it's not going to happen for some time
given the burden we can reasonably place on downstream packagers.

> I'm curious, though, is there some reason you went with the "v5.10.0"
> syntax other than "5.010"?  I believe the latter provides a better error
> message on older Perls, although I agree the former is more readable.

It would only provide confusing errors on 5.6 and older, which as noted
we haven't supported at all since before 2010, so people are unlikely to
be running it.

I'll note why I did that in a non-RFC commit message, FWIW this wording
was also confusing in perl's own documentation, which I fixed the other
day: https://github.com/Perl/perl5/commit/f1546a83e7