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.