[bug#61240] improve high-res file timestamp in Automake

[Sam James]

> On 5 Feb 2023, at 00:02, Jacob Bachmeyer <jcb62281@gmail.com> wrote:
> 
> Paul Eggert wrote:
>> On 2023-02-03 18:27, Jacob Bachmeyer wrote:
>>> Where are you actually using a 5.10 feature?
>> 
>> Where lib/Automake/FileUtils.pm says "use Time::HiRes qw(stat);". This does 
>> not work with Perl 5.6.
> 
> Time::HiRes is (perhaps was) installable from CPAN and is definitely /not/ a 
> 5.10 feature.  I have a Perl 5.8 with it installed, and while my memories 
> that far back are a bit fuzzy, I seem to remember installing Time::HiRes on a 
> Perl 5.6 installation some years ago.  Things like "our" variables, 
> PerlIO-by-default, and the defined-or operator are Perl features (those in 
> 5.6, 5.8, and 5.10 if I remember correctly), modules are (with rare 
> exceptions) not Perl features.
> 
> The correct solution if you do not want to provide for the case where 
> Time::HiRes is not available is to simply "use Time::HiRes qw(stat);" and 
> *let* *that* *fail* if Time::HiRes is not available or cannot export stat().  
> Time::HiRes was on CPAN long before it was bundled with Perl, so the Perl 
> version does /not/ tell you if it is available.  (If Automake::FileUtils is 
> not immediately loaded, put "use Time::HiRes;" somewhere that is.  That will 
> be enough to ensure that Time::HiRes is available.)
> 
>> For why we bumped the version to 5.10, please see:
>> 
>> https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=61901a1a14fd50c03cfb1529d091554376fef286
>> 
>>> Please do not arbitrarily bump version requirements just to bump version 
>>> requirements.
>> 
>> That's not what was done here. The abovementioned URL says version 
>> requirements were bumped from 5.6 to 5.10 because the feature is not present 
>> in 5.6 (2000), is present in 5.10 (2007), and we lacked access to the museum 
>> pieces in the middle. If you are sure that a version number lower than 5.10 
>> will do, please let us know.
> 
> This was arbitrary because Time::HiRes is not actually dependent on the Perl 
> version in that way.  (You should also be able to get access to the museum 
> pieces in the middle fairly easily using perlbrew.)

I think you probably mean "a mistake" rather than "arbitrary". He didn't choose 
it for no reason or for fun.

signature.asc
Description: Message signed with OpenPGP