NAME

       cpanfile-faq - cpanfile FAQ

QUESTIONS

   Does cpanfile replace Makefile.PL/Build.PL or META.yml/json?
       No, it doesn't. "cpanfile" is a simpler way to declare CPAN dependencies, mainly for your application
       rather than CPAN distributions.

       However, while CPAN distributions do not need to switch to "cpanfile", you can certainly manage the
       dependencies in "cpanfile", then export them into "META.json" files when shipping to CPAN, using tools
       such as Dist::Milla or Module::Install::CPANfile

   Why do we need yet another format?
       Here are some of the reasons that motivates the new cpanfile format.

       Not everything is a CPAN distribution
           First of all, it is annoying to write (a dummy) "Makefile.PL" when what you develop is not a CPAN
           distribution, just so that installation like "cpanm --installdeps ." would work.

           It gets more painful when you develop a web application that you want to deploy on a different
           environment using version control system (such as PaaS/cloud infrastructure), because it requires you
           to often commit the META file or "inc/" directory (or even worse, both) to a repository.

           Many web application frameworks generate a boiler-plate "Makefile.PL" for dependency declaration and
           to let you install dependencies with "cpanm --installdeps .", but that doesn't always mean they are
           meant to be installed. Things can be often much simpler if you run the application from the checkout
           directory.

           With cpanfile, dependencies can be installed either globally or locally using supported tools such as
           cpanm or Carton. Because "cpanfile" lists all the dependencies of your entire application and will be
           updated over time, it makes perfect sense to commit the file to a version control system, and push
           the file for a deployment.

       Familiar DSL syntax
           This is a new file type, but the format and syntax isn't entirely new. The metadata it can declare is
           exactly a subset of "Prereqs" in CPAN Meta Spec.

           The syntax borrows a lot from Module::Install. Module::Install is a great way to easily declare
           module metadata such as name, author and dependencies. cpanfile format is simply to extract the
           dependencies into a separate file, which means most of the developers are familiar with the syntax.

       Complete CPAN Meta Spec v2 support
           "cpanfile" basically allows you to declare CPAN::Meta::Spec prerequisite specification using an easy
           Perl DSL syntax. This makes it easy to declare per-phase dependencies and newer version 2 features
           such as conflicts and version ranges.

   How can I start using "cpanfile"?
       First of all, most distributions on CPAN are not required to update to this format.

       If your application currently uses "Makefile.PL" etc. for dependency declaration because of the current
       toolchain implementation (e.g. "cpanm --installdeps ."), you can upgrade to "cpanfile" while keeping the
       build file based installation working for the backward compatibility.

       If you are an author of CPAN module and want to manage CPAN module prerequisites using "cpanfile" you can
       use one of the following tools:

       Dist::Milla
           Dist::Milla is a profile for Dist::Zilla that has a "cpanfile" support to declare dependencies for
           your module.

       Dist::Zilla
           Dist::Zilla::Plugin::Prereqs::FromCPANfile provides a way to merge dependencies declared in
           "cpanfile" into META files as well as build files. You can combine them using other prerequisite
           scanners like "AutoPrereqs".

       Minilla
           Minilla is a yet another authoring tool that supports "cpanfile" as a way to describe dependencies
           for your CPAN module.

       Module::Install
           Module::Install::CPANfile provides a "cpanfile" DSL that reads "cpanfile" to merge prerequisites when
           dumping "MYMETA" files upon installation.

       Module::Build
           Module::Build::Pluggable::CPANfile merges "cpanfile" dependencies from "Build.PL" when dumping out
           MYMETA information.

           However you're recommended to switch to an authoring system that emits "Build.PL" with parsed
           CPANfile information, like Dist::Zilla mentioned above.

       ExtUtils::MakeMaker
           ExtUtils::MakeMaker::CPANfile merges "cpanfile" prerequisites when dumping "MYMETA" files upon
           installation.

           However you're recommended to switch to an authoring system that emits "Makefile.PL" with parsed
           CPANfile information, like Dist::Zilla mentioned above.