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. In fact, you don't
    even need a shell, so even platforms like MacOS (traditional) can use it
    fairly easily. Its only prerequisites are modules that are included with
    perl 5.6.0, and it works fine on perl 5.005 if you can install a few
    additional modules.

    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.

    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,
    $ENV{HOME}/.modulebuildrc. If it's not found there, it will look in the
    the .modulebuildrc file in the directories referred to by the
    environment variables "HOMEDRIVE" + "HOMEDIR", "USERPROFILE", "APPDATA",
    "WINDIR", "SYS$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/>