Installing DBD::mysql on Mavericks

3 years ago, I posted about getting DBD::mysql to build on OSX 10.6 – it seems the same thing works on Mavericks (10.9) as well!

#   Failed test 'use DBD::mysql;'
#   at t/00base.t line 18.
#     Tried to use 'DBD::mysql'.
#     Error:  Can't load '/Users/simon/.cpan/build/DBD-mysql-4.027-wbgMWL/blib/arch/auto/DBD/mysql/mysql.bundle' for module DBD::mysql: dlopen(/Users/simon/.cpan/build/DBD-mysql-4.027-wbgMWL/blib/arch/auto/DBD/mysql/mysql.bundle, 2): Library not loaded: libmysqlclient.18.dylib
#   Referenced from: /Users/simon/.cpan/build/DBD-mysql-4.027-wbgMWL/blib/arch/auto/DBD/mysql/mysql.bundle
#   Reason: image not found at /System/Library/Perl/5.16/darwin-thread-multi-2level/ line 194.
#  at (eval 7) line 2.

The version of MySQL has changed slightly (and hence the path used) but everything else is the same.

$ sudo install_name_tool -id /usr/local/mysql-5.5.30-osx10.6-x86_64/lib/libmysqlclient.18.dylib /usr/local/mysql-5.5.30-osx10.6-x86_64/lib/libmysqlclient.18.dylib

$ otool -D `mdfind libmysqlclient.18.dylib`

cpan2rpm for CentOS 6.5

I’ve been attempting to build all the dependencies for Dancer on CentOS 6.5 and things just kept going wrong. Several of the modules complained about needing perl >= 5.006 even though CentOS 6.5 comes with Perl 5.10.

[mockbuild@build6 ~]$ cpan2rpm Test::Simple

-- cpan2rpm - Ver: 2.028 --
Upgrade check
Fetch: HTTP

-- module: Test::Simple --
Found: Test-Simple-1.001002.tar.gz
Retrieving URL
Metadata retrieval
Tarball extraction: [/home/mockbuild/rpmbuild/SOURCES/Test-Simple-1.001002.tar.gz]
Unable to build module, the following dependencies have failed:
  perl >= 5.006
Stopped at /usr/local/bin/cpan2rpm line 491.

Despite there not being a newer version of cpan2rpm than 2.028 obviously available, there is a development version 2.028_02 which makes it compatible with Perl 5.10.  You have to download it directly from CPAN at and then use cpan2rpm to build it!

[mockbuild@build6 ~]$ cpan2rpm --no-prfx --no-sign ./cpan2rpm-2.028_02.tar.gz

Once it’s built the new cpan2rpm rpm, install it using yum localinstall which will remove the old version at the same time. This new version is able to build the packages for more up to date versions of Test::Simple and URI.

Update: Test::Simple builds but doesn’t pass all the tests, URI is ok.

cpan2rpm on CentOS 6.4

I’ve just been building up a new server with CentOS 6.4 and noticed that cpan2rpm wouldn’t work for some Perl modules. The error you get is as follows.

Metadata retrieval
Can't locate object method "interpolate" via package "Pod::Text" at
/usr/bin/cpan2rpm line 522.

Turns out it’s because Pod::Text changed between the version that comes with CentOS 5 (2.21) and the version with CentOS 6 (3.13) and the interpolate method disappeared.

I found a patch attached to this ticket and when applied to cpan2rpm, it works once more.

DBIx::Class default column value

Having read the docs for DBIx::Class::Row new() and DBIx::Class::ResultSource add_columns() it’s hard to know whether it’s better to (a) override new() for the Result module and set a default value in the method params, or (b) use default_value in the add_columns method and set the default within the database itself.

After some investigation, (b) requires fetching the row after creating it just in case there’s a default value being added by the database. Since I already had a custom new() method to validate one of the parameters anyway, I decided to go for option (a) and add a simple check to new()

$args->{ column_name } = $default unless exists $args->{ column_name };

DBD::mysql, MySQL and OS X Lion

I downloaded and installed MySQL Community Server 5.5.15 from

Using CPAN, I then tried to install DBD::mysql on a fresh install of OS X Lion and was presented with an error saying it was unable to load the library.

#     Error:  Can’t load ‘/private/var/root/.cpan/build/DBD-mysql-4.019-H1RD6j/blib/arch/auto/DBD/mysql/mysql.bundle’ for module DBD::mysql: dlopen(/private/var/root/.cpan/build/DBD-mysql-4.019-H1RD6j/blib/arch/auto/DBD/mysql/mysql.bundle, 2): Library not loaded: libmysqlclient.18.dylib
#   Referenced from: /private/var/root/.cpan/build/DBD-mysql-4.019-H1RD6j/blib/arch/auto/DBD/mysql/mysql.bundle

Continue reading DBD::mysql, MySQL and OS X Lion

Merging two hashrefs in Perl

I came across an interesting and very simple way to merge the contents of two hashrefs today. A hash is made up of pairs – a key and a corresponding value. As an example, the following can be pasted into a shell session on most machines that have perl installed.
perl -MData::Dumper -le ‘
$x = { a => 1, b => 2 };
$y = { c => 3, d => 4 };
$x = { %$x, %$y };
print Dumper($x);

Continue reading Merging two hashrefs in Perl