NAME

    Module::Build - Build and install Perl modules

SYNOPSIS

    Standard process for building & installing modules:

      perl Build.PL
      ./Build
      ./Build test
      ./Build install

    Or, if you're on a platform (like DOS or Windows) that doesn't require
    the "./" notation, you can do this:

      perl Build.PL
      Build
      Build test
      Build install

DESCRIPTION

    Module::Build is a system for building, testing, and installing Perl
    modules. It is meant to be an alternative to ExtUtils::MakeMaker.
    Developers may alter the behavior of the module through subclassing in
    a much more straightforward way than with MakeMaker. It also does not
    require a make on your system - most of the Module::Build code is
    pure-perl and written in a very cross-platform way.

    See "MOTIVATIONS" for more comparisons between ExtUtils::MakeMaker and
    Module::Build.

    To install Module::Build, and any other module that uses Module::Build
    for its installation process, do the following:

      perl Build.PL       # 'Build.PL' script creates the 'Build' script
      ./Build             # Need ./ to ensure we're using this "Build" script
      ./Build test        # and not another one that happens to be in the PATH
      ./Build install

    This illustrates initial configuration and the running of three
    'actions'. In this case the actions run are 'build' (the default
    action), 'test', and 'install'. Other actions defined so far include:

    <action_list>

    You can run the 'help' action for a complete list of actions.

GUIDE TO DOCUMENTATION

    The documentation for Module::Build is broken up into sections:

    General Usage (Module::Build)

      This is the document you are currently reading. It describes basic
      usage and background information. Its main purpose is to assist the
      user who wants to learn how to invoke and control Module::Build
      scripts at the command line.

    Authoring Reference (Module::Build::Authoring)

      This document describes the structure and organization of
      Module::Build, and the relevant concepts needed by authors who are
      writing Build.PL scripts for a distribution or controlling
      Module::Build processes programmatically.

    API Reference (Module::Build::API)

      This is a reference to the Module::Build API.

    Cookbook (Module::Build::Cookbook)

      This document demonstrates how to accomplish many common tasks. It
      covers general command line usage and authoring of Build.PL scripts.
      Includes working examples.

ACTIONS

    There are some general principles at work here. First, each task when
    building a module is called an "action". These actions are listed
    above; they correspond to the building, testing, installing, packaging,
    etc., tasks.

    Second, arguments are processed in a very systematic way. Arguments are
    always key=value pairs. They may be specified at perl Build.PL time
    (i.e. perl Build.PL destdir=/my/secret/place), in which case their
    values last for the lifetime of the Build script. They may also be
    specified when executing a particular action (i.e. Build test
    verbose=1), in which case their values last only for the lifetime of
    that command. Per-action command line parameters take precedence over
    parameters specified at perl Build.PL time.

    The build process also relies heavily on the Config.pm module. If the
    user wishes to override any of the values in Config.pm, she may specify
    them like so:

      perl Build.PL --config cc=gcc --config ld=gcc

    The following build actions are provided by default.

    build

      [version 0.01]

      If you run the Build script without any arguments, it runs the build
      action, which in turn runs the code and docs actions.

      This is analogous to the MakeMaker make all target.

    clean

      [version 0.01]

      This action will clean up any files that the build process may have
      created, including the blib/ directory (but not including the _build/
      directory and the Build script itself).

    code

      [version 0.20]

      This action builds your code base.

      By default it just creates a blib/ directory and copies any .pm and
      .pod files from your lib/ directory into the blib/ directory. It also
      compiles any .xs files from lib/ and places them in blib/. Of course,
      you need a working C compiler (probably the same one that built perl
      itself) for the compilation to work properly.

      The code action also runs any .PL files in your lib/ directory.
      Typically these create other files, named the same but without the
      .PL ending. For example, a file lib/Foo/Bar.pm.PL could create the
      file lib/Foo/Bar.pm. The .PL files are processed first, so any .pm
      files (or other kinds that we deal with) will get copied correctly.

    config_data

      [version 0.26]

      ...

    diff

      [version 0.14]

      This action will compare the files about to be installed with their
      installed counterparts. For .pm and .pod files, a diff will be shown
      (this currently requires a 'diff' program to be in your PATH). For
      other files like compiled binary files, we simply report whether they
      differ.

      A flags parameter may be passed to the action, which will be passed
      to the 'diff' program. Consult your 'diff' documentation for the
      parameters it will accept - a good one is -u:

        ./Build diff flags=-u

    dist

      [version 0.02]

      This action is helpful for module authors who want to package up
      their module for source distribution through a medium like CPAN. It
      will create a tarball of the files listed in MANIFEST and compress
      the tarball using GZIP compression.

      By default, this action will use the Archive::Tar module. However,
      you can force it to use binary "tar" and "gzip" executables by
      supplying an explicit tar (and optional gzip) parameter:

        ./Build dist --tar C:\path\to\tar.exe --gzip C:\path\to\zip.exe

    distcheck

      [version 0.05]

      Reports which files are in the build directory but not in the
      MANIFEST file, and vice versa. (See manifest for details.)

    distclean

      [version 0.05]

      Performs the 'realclean' action and then the 'distcheck' action.

    distdir

      [version 0.05]

      Creates a "distribution directory" named $dist_name-$dist_version (if
      that directory already exists, it will be removed first), then copies
      all the files listed in the MANIFEST file to that directory. This
      directory is what the distribution tarball is created from.

    distinstall

      [version 0.37]

      Performs the 'distdir' action, then switches into that directory and
      runs a perl Build.PL, followed by the 'build' and 'install' actions
      in that directory. Use PERL_MB_OPT or .modulebuildrc to set options
      that should be applied during subprocesses

    distmeta

      [version 0.21]

      Creates the META.yml file that describes the distribution.

      META.yml is a file containing various bits of metadata about the
      distribution. The metadata includes the distribution name, version,
      abstract, prerequisites, license, and various other data about the
      distribution. This file is created as META.yml in a simplified YAML
      format.

      META.yml file must also be listed in MANIFEST - if it's not, a
      warning will be issued.

      The current version of the META.yml specification can be found on
      CPAN as CPAN::Meta::Spec.

    distsign

      [version 0.16]

      Uses Module::Signature to create a SIGNATURE file for your
      distribution, and adds the SIGNATURE file to the distribution's
      MANIFEST.

    disttest

      [version 0.05]

      Performs the 'distdir' action, then switches into that directory and
      runs a perl Build.PL, followed by the 'build' and 'test' actions in
      that directory. Use PERL_MB_OPT or .modulebuildrc to set options that
      should be applied during subprocesses

    docs

      [version 0.20]

      This will generate documentation (e.g. Unix man pages and HTML
      documents) for any installable items under blib/ that contain POD. If
      there are no bindoc or libdoc installation targets defined (as will
      be the case on systems that don't support Unix manpages) no action is
      taken for manpages. If there are no binhtml or libhtml installation
      targets defined no action is taken for HTML documents.

    fakeinstall

      [version 0.02]

      This is just like the install action, but it won't actually do
      anything, it will just report what it would have done if you had
      actually run the install action.

    help

      [version 0.03]

      This action will simply print out a message that is meant to help you
      use the build process. It will show you a list of available build
      actions too.

      With an optional argument specifying an action name (e.g. Build help
      test), the 'help' action will show you any POD documentation it can
      find for that action.

    html

      [version 0.26]

      This will generate HTML documentation for any binary or library files
      under blib/ that contain POD. The HTML documentation will only be
      installed if the install paths can be determined from values in
      Config.pm. You can also supply or override install paths on the
      command line by specifying install_path values for the binhtml and/or
      libhtml installation targets.

      With an optional html_links argument set to a false value, you can
      skip the search for other documentation to link to, because that can
      waste a lot of time if there aren't any links to generate anyway:

        ./Build html --html_links 0

    install

      [version 0.01]

      This action will use ExtUtils::Install to install the files from
      blib/ into the system. See "INSTALL PATHS" for details about how
      Module::Build determines where to install things, and how to
      influence this process.

      If you want the installation process to look around in @INC for other
      versions of the stuff you're installing and try to delete it, you can
      use the uninst parameter, which tells ExtUtils::Install to do so:

        ./Build install uninst=1

      This can be a good idea, as it helps prevent multiple versions of a
      module from being present on your system, which can be a confusing
      situation indeed.

    installdeps

      [version 0.36]

      This action will use the cpan_client parameter as a command to
      install missing prerequisites. You will be prompted whether to
      install optional dependencies.

      The cpan_client option defaults to 'cpan' but can be set as an option
      or in .modulebuildrc. It must be a shell command that takes a list of
      modules to install as arguments (e.g. 'cpanp -i' for CPANPLUS). If
      the program part is a relative path (e.g. 'cpan' or 'cpanp'), it will
      be located relative to the perl program that executed Build.PL.

        /opt/perl/5.8.9/bin/perl Build.PL
        ./Build installdeps --cpan_client 'cpanp -i'
        # installs to 5.8.9

    manifest

      [version 0.05]

      This is an action intended for use by module authors, not people
      installing modules. It will bring the MANIFEST up to date with the
      files currently present in the distribution. You may use a
      MANIFEST.SKIP file to exclude certain files or directories from
      inclusion in the MANIFEST. MANIFEST.SKIP should contain a bunch of
      regular expressions, one per line. If a file in the distribution
      directory matches any of the regular expressions, it won't be
      included in the MANIFEST.

      The following is a reasonable MANIFEST.SKIP starting point, you can
      add your own stuff to it:

        ^_build
        ^Build$
        ^blib
        ~$
        \.bak$
        ^MANIFEST\.SKIP$
        CVS

      See the distcheck and skipcheck actions if you want to find out what
      the manifest action would do, without actually doing anything.

    manifest_skip

      [version 0.3608]

      This is an action intended for use by module authors, not people
      installing modules. It will generate a boilerplate MANIFEST.SKIP file
      if one does not already exist.

    manpages

      [version 0.28]

      This will generate man pages for any binary or library files under
      blib/ that contain POD. The man pages will only be installed if the
      install paths can be determined from values in Config.pm. You can
      also supply or override install paths by specifying there values on
      the command line with the bindoc and libdoc installation targets.

    pardist

      [version 0.2806]

      Generates a PAR binary distribution for use with PAR or PAR::Dist.

      It requires that the PAR::Dist module (version 0.17 and up) is
      installed on your system.

    ppd

      [version 0.20]

      Build a PPD file for your distribution.

      This action takes an optional argument codebase which is used in the
      generated PPD file to specify the (usually relative) URL of the
      distribution. By default, this value is the distribution name without
      any path information.

      Example:

        ./Build ppd --codebase "MSWin32-x86-multi-thread/Module-Build-0.21.tar.gz"

    ppmdist

      [version 0.23]

      Generates a PPM binary distribution and a PPD description file. This
      action also invokes the ppd action, so it can accept the same
      codebase argument described under that action.

      This uses the same mechanism as the dist action to tar & zip its
      output, so you can supply tar and/or gzip parameters to affect the
      result.

    prereq_data

      [version 0.32]

      This action prints out a Perl data structure of all prerequisites and
      the versions required. The output can be loaded again using eval().
      This can be useful for external tools that wish to query a Build
      script for prerequisites.

    prereq_report

      [version 0.28]

      This action prints out a list of all prerequisites, the versions
      required, and the versions actually installed. This can be useful for
      reviewing the configuration of your system prior to a build, or when
      compiling data to send for a bug report.

    pure_install

      [version 0.28]

      This action is identical to the install action. In the future,
      though, when install starts writing to the file
      $(INSTALLARCHLIB)/perllocal.pod, pure_install won't, and that will be
      the only difference between them.

    realclean

      [version 0.01]

      This action is just like the clean action, but also removes the
      _build directory and the Build script. If you run the realclean
      action, you are essentially starting over, so you will have to
      re-create the Build script again.

    retest

      [version 0.2806]

      This is just like the test action, but doesn't actually build the
      distribution first, and doesn't add blib/ to the load path, and
      therefore will test against a previously installed version of the
      distribution. This can be used to verify that a certain installed
      distribution still works, or to see whether newer versions of a
      distribution still pass the old regression tests, and so on.

    skipcheck

      [version 0.05]

      Reports which files are skipped due to the entries in the
      MANIFEST.SKIP file (See manifest for details)

    test

      [version 0.01]

      This will use Test::Harness or TAP::Harness to run any regression
      tests and report their results. Tests can be defined in the standard
      places: a file called test.pl in the top-level directory, or several
      files ending with .t in a t/ directory.

      If you want tests to be 'verbose', i.e. show details of test
      execution rather than just summary information, pass the argument
      verbose=1.

      If you want to run tests under the perl debugger, pass the argument
      debugger=1.

      If you want to have Module::Build find test files with different file
      name extensions, pass the test_file_exts argument with an array of
      extensions, such as [qw( .t .s .z )].

      If you want test to be run by TAP::Harness, rather than
      Test::Harness, pass the argument tap_harness_args as an array
      reference of arguments to pass to the TAP::Harness constructor.

      In addition, if a file called visual.pl exists in the top-level
      directory, this file will be executed as a Perl script and its output
      will be shown to the user. This is a good place to put speed tests or
      other tests that don't use the Test::Harness format for output.

      To override the choice of tests to run, you may pass a test_files
      argument whose value is a whitespace-separated list of test scripts
      to run. This is especially useful in development, when you only want
      to run a single test to see whether you've squashed a certain bug
      yet:

        ./Build test --test_files t/something_failing.t

      You may also pass several test_files arguments separately:

        ./Build test --test_files t/one.t --test_files t/two.t

      or use a glob()-style pattern:

        ./Build test --test_files 't/01-*.t'

    testall

      [version 0.2807]

      [Note: the 'testall' action and the code snippets below are currently
      in alpha stage, see
      "/www.nntp.perl.org/group/perl.module.build/2007/03/msg584.html"" in
      "http: ]

      Runs the test action plus each of the test$type actions defined by
      the keys of the test_types parameter.

      Currently, you need to define the ACTION_test$type method yourself
      and enumerate them in the test_types parameter.

        my $mb = Module::Build->subclass(
          code => q(
            sub ACTION_testspecial { shift->generic_test(type => 'special'); }
            sub ACTION_testauthor  { shift->generic_test(type => 'author'); }
          )
        )->new(
          ...
          test_types  => {
            special => '.st',
            author  => ['.at', '.pt' ],
          },
          ...

    testcover

      [version 0.26]

      Runs the test action using Devel::Cover, generating a code-coverage
      report showing which parts of the code were actually exercised during
      the tests.

      To pass options to Devel::Cover, set the $DEVEL_COVER_OPTIONS
      environment variable:

        DEVEL_COVER_OPTIONS=-ignore,Build ./Build testcover

    testdb

      [version 0.05]

      This is a synonym for the 'test' action with the debugger=1 argument.

    testpod

      [version 0.25]

      This checks all the files described in the docs action and produces
      Test::Harness-style output. If you are a module author, this is
      useful to run before creating a new release.

    testpodcoverage

      [version 0.28]

      This checks the pod coverage of the distribution and produces
      Test::Harness-style output. If you are a module author, this is
      useful to run before creating a new release.

    versioninstall

      [version 0.16]

      ** Note: since only.pm is so new, and since we just recently added
      support for it here too, this feature is to be considered
      experimental. **

      If you have the only.pm module installed on your system, you can use
      this action to install a module into the version-specific library
      trees. This means that you can have several versions of the same
      module installed and use a specific one like this:

        use only MyModule => 0.55;

      To override the default installation libraries in only::config,
      specify the versionlib parameter when you run the Build.PL script:

        perl Build.PL --versionlib /my/version/place/

      To override which version the module is installed as, specify the
      version parameter when you run the Build.PL script:

        perl Build.PL --version 0.50

      See the only.pm documentation for more information on
      version-specific installs.

OPTIONS

 Command Line Options

    The following options can be used during any invocation of Build.PL or
    the Build script, during any action. For information on other options
    specific to an action, see the documentation for the respective action.

    NOTE: There is some preliminary support for options to use the more
    familiar long option style. Most options can be preceded with the --
    long option prefix, and the underscores changed to dashes (e.g.
    --use-rcfile). Additionally, the argument to boolean options is
    optional, and boolean options can be negated by prefixing them with no
    or no- (e.g. --noverbose or --no-verbose).

    quiet

      Suppress informative messages on output.

    verbose

      Display extra information about the Build on output. verbose will
      turn off quiet

    cpan_client

      Sets the cpan_client command for use with the installdeps action. See
      installdeps for more details.

    use_rcfile

      Load the ~/.modulebuildrc option file. This option can be set to
      false to prevent the custom resource file from being loaded.

    allow_mb_mismatch

      Suppresses the check upon startup that the version of Module::Build
      we're now running under is the same version that was initially
      invoked when building the distribution (i.e. when the Build.PL script
      was first run). As of 0.3601, a mismatch results in a warning instead
      of a fatal error, so this option effectively just suppresses the
      warning.

    debug

      Prints Module::Build debugging information to STDOUT, such as a trace
      of executed build actions.

 Default Options File (.modulebuildrc)

    [version 0.28]

    When Module::Build starts up, it will look first for a file,
    $ENV{HOME}/.modulebuildrc. If it's not found there, it will look in the
    .modulebuildrc file in the directories referred to by the environment
    variables HOMEDRIVE + HOMEDIR, USERPROFILE, APPDATA, WINDIR, SYS$LOGIN.
    If the file exists, the options specified there will be used as
    defaults, as if they were typed on the command line. The defaults can
    be overridden by specifying new values on the command line.

    The action name must come at the beginning of the line, followed by any
    amount of whitespace and then the options. Options are given the same
    as they would be on the command line. They can be separated by any
    amount of whitespace, including newlines, as long there is whitespace
    at the beginning of each continued line. Anything following a hash mark
    (#) is considered a comment, and is stripped before parsing. If more
    than one line begins with the same action name, those lines are merged
    into one set of options.

    Besides the regular actions, there are two special pseudo-actions: the
    key * (asterisk) denotes any global options that should be applied to
    all actions, and the key 'Build_PL' specifies options to be applied
    when you invoke perl Build.PL.

      *           verbose=1   # global options
      diff        flags=-u
      install     --install_base /home/ken
                  --install_path html=/home/ken/docs/html
      installdeps --cpan_client 'cpanp -i'

    If you wish to locate your resource file in a different location, you
    can set the environment variable MODULEBUILDRC to the complete absolute
    path of the file containing your options.

 Environment variables

    MODULEBUILDRC

      [version 0.28]

      Specifies an alternate location for a default options file as
      described above.

    PERL_MB_OPT

      [version 0.36]

      Command line options that are applied to Build.PL or any Build
      action. The string is split as the shell would (e.g. whitespace) and
      the result is prepended to any actual command-line arguments.

INSTALL PATHS

    [version 0.19]

    When you invoke Module::Build's build action, it needs to figure out
    where to install things. The nutshell version of how this works is that
    default installation locations are determined from Config.pm, and they
    may be overridden by using the install_path parameter. An install_base
    parameter lets you specify an alternative installation root like
    /home/foo, and a destdir lets you specify a temporary installation
    directory like /tmp/install in case you want to create bundled-up
    installable packages.

    Natively, Module::Build provides default installation locations for the
    following types of installable items:

    lib

      Usually pure-Perl module files ending in .pm.

    arch

      "Architecture-dependent" module files, usually produced by compiling
      XS, Inline, or similar code.

    script

      Programs written in pure Perl. In order to improve reuse, try to make
      these as small as possible - put the code into modules whenever
      possible.

    bin

      "Architecture-dependent" executable programs, i.e. compiled C code or
      something. Pretty rare to see this in a perl distribution, but it
      happens.

    bindoc

      Documentation for the stuff in script and bin. Usually generated from
      the POD in those files. Under Unix, these are manual pages belonging
      to the 'man1' category.

    libdoc

      Documentation for the stuff in lib and arch. This is usually
      generated from the POD in .pm files. Under Unix, these are manual
      pages belonging to the 'man3' category.

    binhtml

      This is the same as bindoc above, but applies to HTML documents.

    libhtml

      This is the same as libdoc above, but applies to HTML documents.

    Four other parameters let you control various aspects of how
    installation paths are determined:

    installdirs

      The default destinations for these installable things come from
      entries in your system's Config.pm. You can select from three
      different sets of default locations by setting the installdirs
      parameter as follows:

                                'installdirs' set to:
                         core          site                vendor
      
                    uses the following defaults from Config.pm:
      
        lib     => installprivlib  installsitelib      installvendorlib
        arch    => installarchlib  installsitearch     installvendorarch
        script  => installscript   installsitescript   installvendorscript
        bin     => installbin      installsitebin      installvendorbin
        bindoc  => installman1dir  installsiteman1dir  installvendorman1dir
        libdoc  => installman3dir  installsiteman3dir  installvendorman3dir
        binhtml => installhtml1dir installsitehtml1dir installvendorhtml1dir [*]
        libhtml => installhtml3dir installsitehtml3dir installvendorhtml3dir [*]
      
        * Under some OS (eg. MSWin32) the destination for HTML documents is
          determined by the C<Config.pm> entry C<installhtmldir>.

      The default value of installdirs is "site". If you're creating vendor
      distributions of module packages, you may want to do something like
      this:

        perl Build.PL --installdirs vendor

      or

        ./Build install --installdirs vendor

      If you're installing an updated version of a module that was included
      with perl itself (i.e. a "core module"), then you may set installdirs
      to "core" to overwrite the module in its present location.

      (Note that the 'script' line is different from MakeMaker -
      unfortunately there's no such thing as "installsitescript" or
      "installvendorscript" entry in Config.pm, so we use the
      "installsitebin" and "installvendorbin" entries to at least get the
      general location right. In the future, if Config.pm adds some more
      appropriate entries, we'll start using those.)

    install_path

      Once the defaults have been set, you can override them.

      On the command line, that would look like this:

        perl Build.PL --install_path lib=/foo/lib --install_path arch=/foo/lib/arch

      or this:

        ./Build install --install_path lib=/foo/lib --install_path arch=/foo/lib/arch

    install_base

      You can also set the whole bunch of installation paths by supplying
      the install_base parameter to point to a directory on your system.
      For instance, if you set install_base to "/home/ken" on a Linux
      system, you'll install as follows:

        lib     => /home/ken/lib/perl5
        arch    => /home/ken/lib/perl5/i386-linux
        script  => /home/ken/bin
        bin     => /home/ken/bin
        bindoc  => /home/ken/man/man1
        libdoc  => /home/ken/man/man3
        binhtml => /home/ken/html
        libhtml => /home/ken/html

      Note that this is different from how MakeMaker's PREFIX parameter
      works. install_base just gives you a default layout under the
      directory you specify, which may have little to do with the
      installdirs=site layout.

      The exact layout under the directory you specify may vary by system -
      we try to do the "sensible" thing on each platform.

    destdir

      If you want to install everything into a temporary directory first
      (for instance, if you want to create a directory tree that a package
      manager like rpm or dpkg could create a package from), you can use
      the destdir parameter:

        perl Build.PL --destdir /tmp/foo

      or

        ./Build install --destdir /tmp/foo

      This will effectively install to "/tmp/foo/$sitelib",
      "/tmp/foo/$sitearch", and the like, except that it will use
      File::Spec to make the pathnames work correctly on whatever platform
      you're installing on.

    prefix

      Provided for compatibility with ExtUtils::MakeMaker's PREFIX
      argument. prefix should be used when you want Module::Build to
      install your modules, documentation, and scripts in the same place as
      ExtUtils::MakeMaker's PREFIX mechanism.

      The following are equivalent.

          perl Build.PL --prefix /tmp/foo
          perl Makefile.PL PREFIX=/tmp/foo

      Because of the complex nature of the prefixification logic, the
      behavior of PREFIX in MakeMaker has changed subtly over time.
      Module::Build's --prefix logic is equivalent to the PREFIX logic
      found in ExtUtils::MakeMaker 6.30.

      The maintainers of MakeMaker do understand the troubles with the
      PREFIX mechanism, and added INSTALL_BASE support in version 6.31 of
      MakeMaker, which was released in 2006.

      If you don't need to retain compatibility with old versions
      (pre-6.31) of ExtUtils::MakeMaker or are starting a fresh Perl
      installation we recommend you use install_base instead (and
      INSTALL_BASE in ExtUtils::MakeMaker). See "Installing in the same
      location as ExtUtils::MakeMaker" in Module::Build::Cookbook for
      further information.

MOTIVATIONS

    There are several reasons I wanted to start over, and not just fix what
    I didn't like about MakeMaker:

      * I don't like the core idea of MakeMaker, namely that make should be
      involved in the build process. Here are my reasons:

      +

	When a person is installing a Perl module, what can you assume
	about their environment? Can you assume they have make? No, but you
	can assume they have some version of Perl.

      +

	When a person is writing a Perl module for intended distribution,
	can you assume that they know how to build a Makefile, so they can
	customize their build process? No, but you can assume they know
	Perl, and could customize that way.

      For years, these things have been a barrier to people getting the
      build/install process to do what they want.

      * There are several architectural decisions in MakeMaker that make it
      very difficult to customize its behavior. For instance, when using
      MakeMaker you do use ExtUtils::MakeMaker, but the object created in
      WriteMakefile() is actually blessed into a package name that's
      created on the fly, so you can't simply subclass ExtUtils::MakeMaker.
      There is a workaround MY package that lets you override certain
      MakeMaker methods, but only certain explicitly preselected (by
      MakeMaker) methods can be overridden. Also, the method of
      customization is very crude: you have to modify a string containing
      the Makefile text for the particular target. Since these strings
      aren't documented, and can't be documented (they take on different
      values depending on the platform, version of perl, version of
      MakeMaker, etc.), you have no guarantee that your modifications will
      work on someone else's machine or after an upgrade of MakeMaker or
      perl.

      * It is risky to make major changes to MakeMaker, since it does so
      many things, is so important, and generally works. Module::Build is
      an entirely separate package so that I can work on it all I want,
      without worrying about backward compatibility with MakeMaker.

      * Finally, Perl is said to be a language for system administration.
      Could it really be the case that Perl isn't up to the task of
      building and installing software? Even if that software is a bunch of
      .pm files that just need to be copied from one place to another? My
      sense was that we could design a system to accomplish this in a
      flexible, extensible, and friendly manner. Or die trying.

TO DO

    The current method of relying on time stamps to determine whether a
    derived file is out of date isn't likely to scale well, since it
    requires tracing all dependencies backward, it runs into problems on
    NFS, and it's just generally flimsy. It would be better to use an MD5
    signature or the like, if available. See cons for an example.

     - append to perllocal.pod
     - add a 'plugin' functionality

AUTHOR

    Ken Williams <kwilliams@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>.

    The latest development version is available from the Git repository at
    <https://github.com/Perl-Toolchain-Gang/Module-Build>

COPYRIGHT

    Copyright (c) 2001-2006 Ken Williams. All rights reserved.

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

SEE ALSO

    perl(1), Module::Build::Cookbook, Module::Build::Authoring,
    Module::Build::API, ExtUtils::MakeMaker

    META.yml Specification: CPAN::Meta::Spec

    http://www.dsmit.com/cons/

    http://search.cpan.org/dist/PerlBuildSystem/