NAME

       Dist::CheckConflicts - declare version conflicts for your dist

VERSION

       version 0.11

SYNOPSIS

           use Dist::CheckConflicts
               -dist => 'Class-MOP',
               -conflicts => {
                   'Moose'                => '1.14',
                   'namespace::autoclean' => '0.08',
               },
               -also => [
                   'Package::Stash::Conflicts',
               ];

           __PACKAGE__->check_conflicts;

DESCRIPTION

       One shortcoming of the CPAN clients that currently exist is that they have no way of
       specifying conflicting downstream dependencies of modules. This module attempts to work
       around this issue by allowing you to specify conflicting versions of modules separately,
       and deal with them after the module is done installing.

       For instance, say you have a module "Foo", and some other module "Bar" uses "Foo". If
       "Foo" were to change its API in a non-backwards-compatible way, this would cause "Bar" to
       break until it is updated to use the new API. "Foo" can't just depend on the fixed version
       of "Bar", because this will cause a circular dependency (because "Bar" is already
       depending on "Foo"), and this doesn't express intent properly anyway - "Foo" doesn't use
       "Bar" at all. The ideal solution would be for there to be a way to specify conflicting
       versions of modules in a way that would let CPAN clients update conflicting modules
       automatically after an existing module is upgraded, but until that happens, this module
       will allow users to do this manually.

       This module accepts a hash of options passed to its "use" statement, with these keys being
       valid:

       -conflicts
           A hashref of conflict specifications, where keys are module names, and values are the
           last broken version - any version greater than the specified version should work.

       -also
           Additional modules to get conflicts from (potentially recursively). This should
           generally be a list of modules which use Dist::CheckConflicts, which correspond to the
           dists that your dist depends on. (In an ideal world, this would be intuited directly
           from your dependency list, but the dependency list isn't available outside of build
           time).

       -dist
           The name of the distribution, to make the error message from check_conflicts more
           user-friendly.

       The methods listed below are exported by this module into the module that uses it, so you
       should call these methods on your module, not Dist::CheckConflicts.

       As an example, this command line can be used to update your modules, after installing the
       "Foo" dist (assuming that "Foo::Conflicts" is the module in the "Foo" dist which uses
       Dist::CheckConflicts):

           perl -MFoo::Conflicts -e'print "$_\n"
               for map { $_->{package} } Foo::Conflicts->calculate_conflicts' | cpanm

       As an added bonus, loading your conflicts module will provide warnings at runtime if
       conflicting modules are detected (regardless of whether they are loaded before or
       afterwards).

METHODS

   conflicts
       Returns the conflict specification (the "-conflicts" parameter to "import()"), as a hash.

   dist
       Returns the dist name (either as specified by the "-dist" parameter to "import()", or the
       package name which "use"d this module).

   check_conflicts
       Examine the modules that are currently installed, and throw an exception with useful
       information if any modules are at versions which conflict with the dist.

   calculate_conflicts
       Examine the modules that are currently installed, and return a list of modules which
       conflict with the dist. The modules will be returned as a list of hashrefs, each
       containing "package", "installed", and "required" keys.

BUGS

       No known bugs.

       Please report any bugs to GitHub Issues at
       <https://github.com/doy/dist-checkconflicts/issues>.

SEE ALSO

       Module::Install::CheckConflicts

       Dist::Zilla::Plugin::Conflicts

SUPPORT

       You can find this documentation for this module with the perldoc command.

           perldoc Dist::CheckConflicts

       You can also look for information at:

       •   MetaCPAN

           <https://metacpan.org/release/Dist-CheckConflicts>

       •   Github

           <https://github.com/doy/dist-checkconflicts>

       •   RT: CPAN's request tracker

           <http://rt.cpan.org/NoAuth/Bugs.html?Dist=Dist-CheckConflicts>

       •   CPAN Ratings

           <http://cpanratings.perl.org/d/Dist-CheckConflicts>

AUTHOR

       Jesse Luehrs <doy@tozt.net>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2014 by Jesse Luehrs.

       This is free software; you can redistribute it and/or modify it under the same terms as
       the Perl 5 programming language system itself.