1=head1 NAME 2 3Module::Build::Bundling - How to bundle Module::Build with a distribution 4 5=head1 SYNOPSIS 6 7 # Build.PL 8 use inc::latest 'Module::Build'; 9 10 Module::Build->new( 11 module_name => 'Foo::Bar', 12 license => 'perl', 13 )->create_build_script; 14 15=head1 DESCRIPTION 16 17B<WARNING -- THIS IS AN EXPERIMENTAL FEATURE> 18 19In order to install a distribution using Module::Build, users must 20have Module::Build available on their systems. There are two ways 21to do this. The first way is to include Module::Build in the 22C<configure_requires> metadata field. This field is supported by 23recent versions L<CPAN> and L<CPANPLUS> and is a standard feature 24in the Perl core as of Perl 5.10.1. Module::Build now adds itself 25to C<configure_requires> by default. 26 27The second way supports older Perls that have not upgraded CPAN or 28CPANPLUS and involves bundling an entire copy of Module::Build 29into the distribution's C<inc/> directory. This is the same approach 30used by L<Module::Install>, a modern wrapper around ExtUtils::MakeMaker 31for Makefile.PL based distributions. 32 33The "trick" to making this work for Module::Build is making sure the 34highest version Module::Build is used, whether this is in C<inc/> or 35already installed on the user's system. This ensures that all necessary 36features are available as well as any new bug fixes. This is done using 37the experimental L<inc::latest> module, available on CPAN. 38 39A "normal" Build.PL looks like this (with only the minimum required 40fields): 41 42 use Module::Build; 43 44 Module::Build->new( 45 module_name => 'Foo::Bar', 46 license => 'perl', 47 )->create_build_script; 48 49A "bundling" Build.PL replaces the initial "use" line with a nearly 50transparent replacement: 51 52 use inc::latest 'Module::Build'; 53 54 Module::Build->new( 55 module_name => 'Foo::Bar', 56 license => 'perl', 57 )->create_build_script; 58 59For I<authors>, when "Build dist" is run, Module::Build will be 60automatically bundled into C<inc> according to the rules for 61L<inc::latest>. 62 63For I<users>, inc::latest will load the latest Module::Build, whether 64installed or bundled in C<inc/>. 65 66=head1 BUNDLING OTHER CONFIGURATION DEPENDENCIES 67 68The same approach works for other configuration dependencies -- modules 69that I<must> be available for Build.PL to run. All other dependencies can 70be specified as usual in the Build.PL and CPAN or CPANPLUS will install 71them after Build.PL finishes. 72 73For example, to bundle the L<Devel::AssertOS::Unix> module (which ensures a 74"Unix-like" operating system), one could do this: 75 76 use inc::latest 'Devel::AssertOS::Unix'; 77 use inc::latest 'Module::Build'; 78 79 Module::Build->new( 80 module_name => 'Foo::Bar', 81 license => 'perl', 82 )->create_build_script; 83 84The C<inc::latest> module creates bundled directories based on the packlist 85file of an installed distribution. Even though C<inc::latest> takes module 86name arguments, it is better to think of it as bundling and making 87available entire I<distributions>. When a module is loaded through 88C<inc::latest>, it looks in all bundled distributions in C<inc/> for a 89newer module than can be found in the existing C<@INC> array. 90 91Thus, the module-name provided should usually be the "top-level" module 92name of a distribution, though this is not strictly required. For example, 93L<Module::Build> has a number of heuristics to map module names to 94packlists, allowing users to do things like this: 95 96 use inc::latest 'Devel::AssertOS::Unix'; 97 98even though Devel::AssertOS::Unix is contained within the Devel-CheckOS 99distribution. 100 101At the current time, packlists are required. Thus, bundling dual-core 102modules, I<including Module::Build>, may require a 'forced install' over 103versions in the latest version of perl in order to create the necessary 104packlist for bundling. This limitation will hopefully be addressed in a 105future version of Module::Build. 106 107=head2 WARNING -- How to Manage Dependency Chains 108 109Before bundling a distribution you must ensure that all prerequisites are 110also bundled and load in the correct order. For Module::Build itself, this 111should not be necessary, but it is necessary for any other distribution. 112(A future release of Module::Build will hopefully address this deficiency.) 113 114For example, if you need C<Wibble>, but C<Wibble> depends on C<Wobble>, 115your Build.PL might look like this: 116 117 use inc::latest 'Wobble'; 118 use inc::latest 'Wibble'; 119 use inc::latest 'Module::Build'; 120 121 Module::Build->new( 122 module_name => 'Foo::Bar', 123 license => 'perl', 124 )->create_build_script; 125 126Authors are strongly suggested to limit the bundling of additional 127dependencies if at all possible and to carefully test their distribution 128tarballs on older versions of Perl before uploading to CPAN. 129 130=head1 AUTHOR 131 132David Golden <dagolden@cpan.org> 133 134Development questions, bug reports, and patches should be sent to the 135Module-Build mailing list at <module-build@perl.org>. 136 137Bug reports are also welcome at 138<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Module-Build>. 139 140=head1 SEE ALSO 141 142perl(1), L<inc::latest>, L<Module::Build>(3), L<Module::Build::API>(3), 143L<Module::Build::Cookbook>(3), 144 145=cut 146 147# vim: tw=75 148