NAME¶
Module::Build::Bundling - How to bundle Module::Build with a distribution
SYNOPSIS¶
# Build.PL
use inc::latest 'Module::Build';
Module::Build->new(
module_name => 'Foo::Bar',
license => 'perl',
)->create_build_script;
DESCRIPTION¶
WARNING -- THIS IS AN EXPERIMENTAL FEATURE
In order to install a distribution using Module::Build, users must have
Module::Build available on their systems. There are two ways to do this. The
first way is to include Module::Build in the "configure_requires"
metadata field. This field is supported by recent versions CPAN and CPANPLUS
and is a standard feature in the Perl core as of Perl 5.10.1. Module::Build
now adds itself to "configure_requires" by default.
The second way supports older Perls that have not upgraded CPAN or CPANPLUS and
involves bundling an entire copy of Module::Build into the distribution's
"inc/" directory. This is the same approach used by Module::Install,
a modern wrapper around ExtUtils::MakeMaker for Makefile.PL based
distributions.
The "trick" to making this work for Module::Build is making sure the
highest version Module::Build is used, whether this is in "inc/" or
already installed on the user's system. This ensures that all necessary
features are available as well as any new bug fixes. This is done using the
new inc::latest module.
A "normal" Build.PL looks like this (with only the minimum required
fields):
use Module::Build;
Module::Build->new(
module_name => 'Foo::Bar',
license => 'perl',
)->create_build_script;
A "bundling" Build.PL replaces the initial "use" line with a
nearly transparent replacement:
use inc::latest 'Module::Build';
Module::Build->new(
module_name => 'Foo::Bar',
license => 'perl',
)->create_build_script;
For
authors, when "Build dist" is run, Module::Build will be
automatically bundled into "inc" according to the rules for
inc::latest.
For
users, inc::latest will load the latest Module::Build, whether
installed or bundled in "inc/".
BUNDLING OTHER CONFIGURATION DEPENDENCIES¶
The same approach works for other configuration dependencies -- modules that
must be available for Build.PL to run. All other dependencies can be
specified as usual in the Build.PL and CPAN or CPANPLUS will install them
after Build.PL finishes.
For example, to bundle the Devel::AssertOS::Unix module (which ensures a
"Unix-like" operating system), one could do this:
use inc::latest 'Devel::AssertOS::Unix';
use inc::latest 'Module::Build';
Module::Build->new(
module_name => 'Foo::Bar',
license => 'perl',
)->create_build_script;
The "inc::latest" module creates bundled directories based on the
packlist file of an installed distribution. Even though
"inc::latest" takes module name arguments, it is better to think of
it as bundling and making available entire
distributions. When a module
is loaded through "inc::latest", it looks in all bundled
distributions in "inc/" for a newer module than can be found in the
existing @INC array.
Thus, the module-name provided should usually be the "top-level"
module name of a distribution, though this is not strictly required. For
example, Module::Build has a number of heuristics to map module names to
packlists, allowing users to do things like this:
use inc::latest 'Devel::AssertOS::Unix';
even though Devel::AssertOS::Unix is contained within the Devel-CheckOS
distribution.
At the current time, packlists are required. Thus, bundling dual-core modules,
including Module::Build, may require a 'forced install' over versions
in the latest version of perl in order to create the necessary packlist for
bundling. This limitation will hopefully be addressed in a future version of
Module::Build.
WARNING -- How to Manage Dependency Chains¶
Before bundling a distribution you must ensure that all prerequisites are also
bundled and load in the correct order. For Module::Build itself, this should
not be necessary, but it is necessary for any other distribution. (A future
release of Module::Build will hopefully address this deficiency.)
For example, if you need "Wibble", but "Wibble" depends on
"Wobble", your Build.PL might look like this:
use inc::latest 'Wobble';
use inc::latest 'Wibble';
use inc::latest 'Module::Build';
Module::Build->new(
module_name => 'Foo::Bar',
license => 'perl',
)->create_build_script;
Authors are strongly suggested to limit the bundling of additional dependencies
if at all possible and to carefully test their distribution tarballs on older
versions of Perl before uploading to CPAN.
AUTHOR¶
David Golden <dagolden@cpan.org>
Development questions, bug reports, and patches should be sent to the
Module-Build mailing list at <module-build@perl.org>.
Bug reports are also welcome at
<
http://rt.cpan.org/NoAuth/Bugs.html?Dist=Module-Build>.
SEE ALSO¶
perl(1), inc::latest, Module::Build(3), Module::Build::API(3),
Module::Build::Cookbook(3),