Removing Modules from Core

I was on holiday last week and missed most of the discussions about removing Module::Build and CGI from the Perl core in the next few years. I hope you won’t mind if I chime in a little late with my thoughts.

Module::Build

I’m a little bemused by the Module::Build story. Well, perhaps “bemused” isn’t quite the right word. Perhaps I should say “embarrassed”. Embarrassed because the discussions around Module::Build just show how out of touch I am with important parts of the Perl ecosystem.

I remember seeing Schwern’sย MakeMaker Is DOOMED! talk ten years ago. What he said made a lot of sense to me and I switched all of my CPAN modules to Module::Build over the next few years. And then I rather took my eye off the ball. I was vaguely aware that people were complaining about Module::Build and were switching to things like Module::Install and Dist::Zilla. But I was happy with Module::Build and just stuck with it.

Now I’m hearing people saying that Module::Build is fundamentally flawed. Someone whose opinion I value mentioned that he lowers his estimate of the IQ of any CPAN author who uses Module::Build. That, presumably, includes me. But when I ask people what the problems are with Module::Build, I can’t get anyone to give me a detailed and dispassionate answer.

I’m quite prepared to believe that there are problems with Module::Build. Given the calibre of the people who are telling me that these problems exist, it would be astonishing if it wasn’t true. But it would be nice if there was a good explanation available somewhere of just what these problems are.

And I think that this is indicative of a deeper problem that the Perl community has. I like to think that I’m pretty much in touch with what is going on in the Perl community. I read the blogs. I’m subscribed to (too many) mailing lists. But it appears I’m not following discussions of the CPAN toolchain closely enough. I guess it’s something that I just expect to work. And I guess I expect that if there are important discussions going on, then I’ll hear about them through other channels – blog posts, for example. But that doesn’t seem to have happened here. Of course I can subscribe myself to another mailing list or two to correct that, but I don’t think I’m unusual in not trying to follow every single Perl discussion. There are surely many people like me who would like information like this to be disseminated better. This is part of the reason why Leo and I set up the Perl News site. But we have a tiny number of editors and we can’t know everything that is worth publishing. If you think we’ve missed an interesting story then please let us know about it.

So I’m not going to object to Module::Build leaving the core. I’m sure there are good reasons, I just wish I knew what they are. I am, however, slightly disappointed to find that Schwern was wrong ten years ago and that ExtUtils::MakeMaker wasn’t doomed.

CGI

CGI.pm and I go back a long way. In fact I think CGI.pm was added to the Perl core at about the same time as I started using Perl.

It’s obvious why it was added to the core. Back in 1997, Perl and CGI were tightly bound together in many people’s minds. I had people telling me that Perl could only be used to write CGI programs and other people telling me that CGI programs could only be written in Perl. Both sets of people were, of course, wrong; but it’s easy to see how they reached both of those conclusions.

Before CGI.pm was added to the Perl core, people used to parse CGI parameters using horribly broken code copied from Matt Wright (code which he had originally copied from Reuven Lerner). Of course, adding the module to the Perl core didn’t magically rewrite all those horrible CGI programs to use CGI::params, but at least it meant that the option was there.

This became important to me when I started the nms project. This project rewrote Matt Wright’s scripts using a better standard of Perl code. The problem was that many people started by installing one of Matt’s scripts on their server and later, when they wanted to move on from using other people’s code, they would use Matt’s code as a template for their own first steps into Perl. This is partly what made Perl so popular. But it’s also what lead to the preponderance of terrible Perl code that you still find on the web today.

We wrote the nms programs to work, as far as possible, in the same environment as Matt’s scripts. Matt said that his scripts would work fine on Perl 4 (back then, there were still many cheap hosting plans that came with Perl 4). We decided not to put ourselves through that pain and to target Perl 5.004 – because that was the first version to include CGI.pm. Remember, we were targeting Matt Wright’s users. And they were people who used cheap hosting plans with basic FTP access and little or no chance of installing anything from CPAN. We had to rely on core modules. If CGI.pm hadn’t been in the Perl core, then the nms programs would have been far harder to write and the project may have never been started.

The nms project was started over ten years ago. What is the situation like now? Those cheap hosting plans still exist. People still use them for simple web sites. Some of those people still use Matt’s scripts or the nms alternatives. But the numbers of people using those programs are far smaller than they used to be. These days, people wanting to add simple dynamic functionality to a web site are far more likely to use a PHP program. And those cheap web hosts are far more likely to want to support PHP.

Of course, these days, no serious Perl developer uses CGI.pm to write web programs. We’d be far more likely to use something based on PSGI. And even if we did want to use CGI.pm, we’d know how to get it installed from CPAN. The only people who are going to suffer from the removal of CGI.pm are the people using something like the nms programs on a cheap hosting plan. I worry a little about the influx of support email we will get when some cheap hosting company updates from Perl 5.18 to Perl 5.22 and suddenly all the nms programs stop working. It’s slightly galling to realise that Matt’s scripts will continue to work at that point. Of course, the kinds of companies that we’re talking about tend to lag well behind the bleeding edge of Perl versions, so this might not happen for eight or more years. So I think it might well be someone else’s problem.

All in all, I think it will be sad to see CGI.pm removed from the core. It will effectively see the end of even half-decent Perl code being used on bottom of the range hosting plans. But Perl has been losing that market for years and, speaking as someone who spent a lot of time helping out on support forums for basic Perl/CGI code, I’m far from convinced that I’ll miss those users. So my sadness at seeing CGI,pm go, will be purely historical.

But I’d really like to see some cut-down version of PSGI take its place!


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7 responses to “Removing Modules from Core”

  1. Peter Scott Avatar

    I agree with you, Dave. I switched to Module::Build for exactly the same reason.

    I think a heck of a lot of stuff is going to break when CGI leaves the core. Considering how much backward compatibility is otherwise valued on p5p, I think this is an odd decision.

  2. Leon Timmermans Avatar
    Leon Timmermans

    David Golden wrote a write-up here about Module::Build.

    As for CGI.pm, it only breaks if your hosting company is too incompetent to install it, in which case you have bigger issues than “it doesn’t work here anymore” IMO.

    1. Dave Cross Avatar

      Yes, but the kinds of hosting companies where people use Matt’s scripts or the nms programs are exactly the kinds of hosting companies where the admins don’t care enough about Perl to keep up to date with changes like this and will have absolutely no interest in installing and supporting extra modules from CPAN.

      I know it’s hard to believe that companies like this or that people would use them to host Perl/CGI programs. But trust me, they do.

      But, as I said above, the incompetence and laziness of these companies might even count in our favour here. They are very unlikely to upgrade to a version of Perl without CGI.pm for a very long time.

  3. Ken Williams Avatar

    Hi Dave – FWIW, I also missed all the Module::Build discussion until after all the decisions were made too.

    I decided to just go on with development as if people still use & want M::B – because I know for many people, it’s true. Removal from core does piss me off, in sort of (a much smaller version of) the way one would feel when one’s child goes off into the world and then is rejected by the spouse you thought would be their lifelong partner. But you just take that child back & try to nurture it & help it thrive again.

    If we end up with much better tools replacing M::B in the core, that’s a great outcome & I’ll be happy to just put M::B in life-support mode & encourage people to switch. I can’t say I see those tools yet though, much less the robustness that comes with time. I’m a relatively happy Dist::Zilla user FWIW, but it’s really not the same niche.

    One of the hardest things for me on M::B is to try to filter the legitimate gripes or requests from the non-useful noise of detractors. It’s hard to tell the difference sometimes, and the latter takes a lot of effort if I get sucked into a debate. Haven’t figured out how to avoid that yet. =)

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