NAME

       Config::Model::Dpkg::Dependency - Checks Debian dependency declarations

SYNOPSIS

        use Config::Model ;
        use Log::Log4perl qw(:easy) ;
        use Data::Dumper ;

        Log::Log4perl->easy_init($WARN);

        # define configuration tree object
        my $model = Config::Model->new ;
        $model ->create_config_class (
           name => "MyClass",
           element => [
               Depends => {
                   'type'       => 'leaf',
                   'value_type' => 'uniline',
                   class => 'Config::Model::Dpkg::Dependency',
               },
           ],
        ) ;

        my $inst = $model->instance(root_class_name => 'MyClass' );

        my $root = $inst->config_root ;

        $root->load( 'Depends="libc6 ( >= 1.0 )"') ;
        # Connecting to qa.debian.org to check libc6 versions. Please wait ...
        # Warning in 'Depends' value 'libc6 ( >= 1.0 )': unnecessary
        # versioned dependency: >= 1.0. Debian has lenny-security ->
        # 2.7-18lenny6; lenny -> 2.7-18lenny7; squeeze-security ->
        # 2.11.2-6+squeeze1; squeeze -> 2.11.2-10; wheezy -> 2.11.2-10; sid
        # -> 2.11.2-10; sid -> 2.11.2-11;

DESCRIPTION

       This class is derived from Config::Model::Value. Its purpose is to check the value of a
       Debian package dependency for the following:

       •   syntax as described in http://www.debian.org/doc/debian-policy/ch-relationships.html

       •   Whether the version specified with ">" or ">=" is necessary.  This module checks with
           Debian server whether older versions can be found in Debian old-stable or not. If no
           older version can be found, a warning is issued (unless the package is known or
           calculated to be virtual)

       •   Whether a Perl library is dual life. In this case the dependency is checked according
           to Debian Perl policy <http://pkg-
           perl.alioth.debian.org/policy.html#debian_control_handling>.  Because Debian auto-
           build systems (buildd) will use the first available alternative, the dependency should
           be in the form :

           •   "perl (>= 5.10.1) | libtest-simple-perl (>= 0.88)" when the required perl version
               is available in sid. ".

           •   "libcpan-meta-perl | perl (>= 5.13.10)" when the Perl version is not available in
               sid

Cache

       Queries to Debian server are cached in "~/.config_model_depend_cache" for about one month.

BUGS

       •   Dependencies containing variables (e.g. "${foo}") are accepted as-is. No check are
           performed.

       •   Virtual package names are found scanning local apt cache. Hence an unknown package on
           your system may be a virtual package on another system.

       •   More advanced checks can probably be implemented. The author is open to new ideas.
           He's even more open to patches (with tests).

AUTHOR

       Dominique Dumont, ddumont [AT] cpan [DOT] org

SEE ALSO

       Config::Model, Config::Model::Value, Memoize, Memoize::Expire