How can I install Perl's DBI on Mac OS X so Apache can find it?

Question

I'm trying to setup a Perl development environment on my Mac laptop and have been having a really hard time getting it working. I thought I had everything configured correctly but when I try to run a sample script it is reporting errors with the DBI module and can't access the DB.

Here is what is reported in the Apache error logs:

[Fri Apr 30 23:11:33 2010] [error] [client 127.0.0.1] Can't locate DBI.pm in @INC (@INC contains: /Library/Perl/Updates/5.10.0/darwin-thread-multi-2level /Library/Perl/Updates/5.10.0 /System/Library/Perl/5.10.0/darwin-thread-multi-2level /System/Library/Perl/5.10.0 /Library/Perl/5.10.0/darwin-thread-multi-2level /Library/Perl/5.10.0 /Network/Library/Perl/5.10.0/darwin-thread-multi-2level /Network/Library/Perl/5.10.0 /Network/Library/Perl /System/Library/Perl/Extras/5.10.0/darwin-thread-multi-2level /System/Library/Perl/Extras/5.10.0 .) at main.pm line 5.

I downloaded and installed both modules manually to work with MAMP using the following commands as specified in this forum post:

For DBI

1. cd /Library/Perl/DBI-1.611 
2. sudo Perl Makefile.PL 
3. sudo make 
4. sudo make install 

For DBD

1. cd /Library/Perl/DBD-mysql-4.014 
2. sudo Perl Makefile.PL --mysql_config=/Applications/MAMP/Library/bin/mysql_config 
3. sudo make 
4. sudo make install 

What I noticed while running the above commands is that the files seems to be getting installed in the '/opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/' directory which doesn't seem to be one of the search directories that Apache mentions in the error at the beginning of this post. Here is what I'm seeing during the install:

$ sudo make install
Files found in blib/arch: installing files in blib/lib into architecture dependent library tree
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/auto/DBI/DBI.bundle
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/auto/DBI/dbipport.h
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/auto/DBI/DBIXS.h
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/auto/DBI/dbixs_rev.h
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/auto/DBI/Driver.xst
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/auto/DBI/Driver_xst.h
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/DBI.pm
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/TASKS.pod
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/DBD/DBM.pm
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/DBD/File.pm
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/DBD/Gofer.pm
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/DBI/Changes.pm
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/DBI/DBD.pm
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/DBI/Profile.pm
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/DBI/ProxyServer.pm
Installing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/DBI/PurePerl.pm
Installing /opt/local/share/man/man3/DBD::DBM.3pm
Installing /opt/local/share/man/man3/DBD::File.3pm
Installing /opt/local/share/man/man3/DBD::Gofer.3pm
Installing /opt/local/share/man/man3/DBI.3pm
Installing /opt/local/share/man/man3/DBI::DBD.3pm
Installing /opt/local/share/man/man3/DBI::Profile.3pm
Installing /opt/local/share/man/man3/DBI::ProxyServer.3pm
Installing /opt/local/share/man/man3/DBI::PurePerl.3pm
Installing /opt/local/share/man/man3/TASKS.3pm
Installing /opt/local/bin/dbiprof
Installing /opt/local/bin/dbiproxy
Writing /opt/local/lib/perl5/site_perl/5.8.9/darwin-2level/auto/DBI/.packlist
Appending installation info to /opt/local/lib/perl5/5.8.9/darwin-2level/perllocal.pod

My question is, what am I doing wrong and how can I either 1) Get Apache to look in the right directory where the DBD & DBI modules are installed or 2) Update the way I'm installing the module to install them into one of the search directories. I honestly don't know what option makes more sense and could use guidance on that as well.

As you can probably tell I'm pretty lost at the moment. Please help!!! Thanks in advance.

Answer 1

It looks like you've already installed another Perl via macports (/opt/local is where all macports installations go), and /opt/local/bin is earlier in your $PATH than the system Perl in /usr/bin. That's fine, if you are happy running Perl 5.8.9 rather than Perl 5.10.0 (hint: if you aren't sure of the differences, then the differences don't matter).

It's usually advised to not make extra installations to the system Perl. Apple may upgrade components through regular system updates, which could interfere with any modifications you have made, and if you make a mistake with an installation, it's difficult to remedy it without doing a full system reinstallation or having some serious understanding of the operating system guts. So, since you've already got another Perl installation ready, I would strongly encourage you to stick with that one.

However, you probably shouldn't be manually installing libraries if there is already a distribution available on macports. I used port search dbi and port search dbd to find them: the distributions are named p5-dbi and p5-dbd-mysql. You can install those like any other macports module: with sudo port install <distroname>. (You may need to install mod_perl itself, too.)

After that, you simply need to tell Apache/mod_perl to use that Perl installation rather than the system perl. I've never done that, so I can't advise on the best way to do it. However, quick searches on http://superuser.com suggest that the macports version of apache will run by default (via the same $PATH ordering), so I'd just Try It And See :).

Answer 2

Great answer, Ether. Having done this far too many times to count, I can give you a few pieces of advice:

Note: I am apparently limited to a single link in the post, so I had to remove all of my annotations. Thankfully, there is Delicious where I've stored them all with a stackoverflowmacports tag. Any place below where I removed a link to fit under Stack Overflow's ridiculous anti-spam measure, I've marked it with (*).

1. If having a reliably-working development environment at all times is important to you, rely on as LITTLE Mac OS X bundled software as possible. I love Apple but they have absolutely no qualms about breaking custom setups of their software as often as possible.

2. If #1 sounds like what you need to do, Macports is an EXCELLENT choice. I used to use Fink but they got left in the dust ages ago in terms of ease of use and spectrum of available software. The easiest route to installing macports is via the binary package install method (*)

3. As Ether mentions, when you have everything set up correctly, the Macports-provided MySQL, PHP and Apache all work together well without the system-installed analogs interfering. Most of that has to do with your PATH setting but all of those details are handled by the package installers post-flight script (*)

4. Once you're on the Macports train, it should become the very first place you look for any software. port search and port info are constant companions. They've got 6863 ports (*) currently which covers MOST of your bases.

5. When you do need to go outside of the Macports realm to find something, install it in /usr/local. That part of the file system hierarchy is yours to play with. Don't be lulled into a false sense of security and think that because Macports doesn't have what you're installing, it's okay to put it in /opt/local because invariably that software will install some dependency that will ALSO be a dependency for some piece of Macports software down the line and Macports will not allow a port to be installed if any one of its files would overwrite an existing file not managed by Macports (unless you force it which is always bad manners)

6. If you do any work with Perl and you use Macports' version, you will absolutely find yourself in a situation Macports doesn't have the one CPAN module you're looking for. (And, really, given that there are two and a half billion CPAN modules, who can blame them?). This will happen often enough that you will most likely tire of the manual installation method (*) (perl Makefile.PL; make; make test; sudo make install; cha; cha; cha) and long for the ease of use you've grown accustomed to with Macports.

   If so, you can absolutely use the cpan (*) utility, CPANPLUS (*) or cpanminus (*) for all of your installing needs. Just make sure to make the necessary adjustments in the configuration of your tool of choice to instruct it to install your modules into /usr/local/lib/perl5, ignoring /opt/local/bin/perl's insistence that modules go into /opt/local/lib/perl5. You can set the PERL5LIB environment variable in your shell's init scripts to additionally look in /usr/local/lib/perl5 for modules. Just grab the @INC output from perl -V and tack it on the end...

7. And finally... Leveraging the system's daily init scripts or third-party software like Anacron (*) or MacPorts Notifier (*) (both available through MacPorts), make sure to update your software frequently. You don't have Mother Apple protecting you with Software Updates for the Macports installed software which have just as many bugs and security exploits as the very same software Apple bundles.

   By updating frequently, you'll stay ahead of the baddies and by automating it, the upgrades will actually happen and you won't end up as I have in the past with a full weekend blown because you had a mountain of outdated ports to upgrade. Note: Macports stages its updates and if it fails at any point, your current version continues to work. Apple could learn a thing or two from them, I tell ya...

So, that's all I can think of a the moment. Hopefully the lessons above will get you going quickly and save all of the time, effort and stress I've experienced in past years in learning it. I would argue it's still far better than the alternative: Hating Apple because they break all of your nice things... :-)

Answer 3

Thank you very much for the detailed answer above, Jay. I have a question concerning #6:

"Just make sure to make the necessary adjustments in the configuration of your tool of choice to instruct it to install your modules into /usr/local/lib/perl5, ignoring /opt/local/bin/perl's insistence that modules go into /opt/local/lib/perl5."

To achieve this I did the following:

cpan> o conf makepl_arg "INSTALLBIN=/usr/local/bin INSTALLSCRIPT=/usr/local/bin"
cpan> o conf commit

"You can set the PERL5LIB environment variable in your shell's init scripts to additionally look in /usr/local/lib/perl5 for modules. Just grab the @INC output from perl -V and tack it on the end..."

I've looked into this quite a bit, using perl -V just produces a long list of /opt/local/lib/perl5/ stuff...don't I want /usr/local/ stuff? I'm confused, could you be more explicit? I tried putting the following in my .profile file:

export PERL5LIB=/usr/local:$PERL5LIB

Sadly, I still get all sorts of crap like:

ERROR: Can't create '/opt/local/lib/perl5/site_perl/5.8.9/Probe'
mkdir /opt/local/lib/perl5/site_perl: Permission denied at /opt/local/lib/perl5/5.8.9/ExtUtils/Install.pm line 457

Any advice is sorely appreciated. Thanks.