The DarkPAN matters

There is currently some FUD going about in some parts of the Perl community about why we should break Perl 5 backwards compatibility. A short blog entry, schmarkpan, is a good example of the trend: loud, noisy, but clueless and devoid of any content.

The author writes, DarkPAN was discussed quite a bit at YAPC::NA. But really, what is it? How is it defined? Well, DarkPAN is just a slang word to express the fact that Perl 5 is now currently used all over the world in production and sometimes critical systems: websites with high availibility, financial systems, operating system build processes, and so on. That would also include the so-called GreyPAN, all Perl OSS applications that are not on CPAN. So, asking this question, even rhetorically, makes you sound as if you didn't knew that Perl is actually used in production.

He continues, Who are these people that have a vested interested in Perl and yet do not participate? For a start, I would like to point out that Mr Perez himself is someone with apparently some interest in Perl, but who does not participate in Perl 5 at the slightest. I might be biased, but I tend to think that the regular contributors of perl5-porters are a lot more likely to have informed opinions about the Perl 5 core development than people who don't even read it.

I think attempting to appease a faceless entity with no defined boundaries has fail written all over it. It is fear mongering. Who's the fear monger here? And who's trying to be realistic by attempting to release software with some quality expectations, notably by making the upgrade process seamless and introducing as little bugs as possible? It's a well-known political technique to accuse the opposite party of being guilty of one's own defects. But it doesn't make you right.

If we break it, they can choose not to upgrade. Several fallacies in one single sentence. First, we should not consider breaking it. Breakage happens, but our goal is to avoid it. Secondly, breakage is detected after upgrades, usually (or it would have been avoided). Third, this not only applies to Perl 5, but also to every open source project widely used (in the Perl world, DBI or LWP come to mind -- upgrading them is not a trivial operation either.) This is a matter of common sense.

Then, suddenly and without warning, the discussion shifts from breaking backwards compatibility to simply breaking Perl: What about bug fixes?, I hear you say. That is the joy of open source. There are lots of unemployed hackers out there that would be willing to backport those fixes for you. Oh heavens forbid! Actually paying open source hackers to write code! The sky is falling! Wishful thinking at its finest. Mr Perez might have found a tuit tree in the middle of a magic garden, but I have never seen "lots of unemployed hackers" who are at the same time fluent in the Perl internals, and lots of generous donators that fight over the privilege of paying them to work on Perl. Actually, there is one, currently: Dave Mitchell, who is paid to get 5.10.1 released. Yes, paid: the sky is falling.

Perl does not belong to DarkPAN. It belongs to us who participate in its wellbeing. In other words, "fuck the users". But we're not in the land of toy projects here. We can't bless any change (or revert it two releases afterwards) just because it looks shiny at the time. This is not the parrot you're looking for. People do use Perl 5 for serious things, and we must ensure that a certain level of quality is preserved.

But have you, Mr Perez, even skimmed through a perldelta manpage, to look at the list of incompatible changes? Because there's actually a lot of them, in spite of what you seem to believe. I had code that broke because strict is stricter in 5.10 (as mentioned in the manual that you didn't bother to read.) ghc broke because we removed the magical variable $*. It's not like we fear incompatible change. We just don't like to introduce incompatible changes just for the sake of being incompatible.

I say we make the decisions best for our language of choice. But code changes don't happen because someone yells about it on a blog. They happen because someone actually writes code. If you really want to see something changed in Perl 5, write a patch and come discussing it on P5P. Although you might not have an idea about what you might want to see changed in Perl 5, since your empty, uninformed and slightly inconsistent rant fails to identify any precise problem.