Module::Build

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Module::Build(3)     User Contributed Perl Documentation     Module::Build(3)



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 "Mod-
       ule::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:

	 build				manpages
	 clean				pardist
	 code				ppd
	 config_data			ppmdist
	 diff				prereq_data
	 dist				prereq_report
	 distcheck			pure_install
	 distclean			realclean
	 distdir			retest
	 distmeta			skipcheck
	 distsign			test
	 disttest			testall
	 docs				testcover
	 fakeinstall			testdb
	 help				testpod
	 html				testpodcoverage
	 install			versioninstall
	 manifest

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

GUIDE TO DOCUMENTATION
       The documentation for "Module::Build" is broken up into three sec-
       tions:

       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 "Mod-
	   ule::Build" scripts at the command line.

       Authoring Reference (Module::Build::Authoring)
	   This document describes the structure and organization of "Mod-
	   ule::Build", and the relevant concepts needed by authors who are
	   writing Build.PL scripts for a distribution or controlling "Mod-
	   ule::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, packag-
       ing, 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 life-
       time of that command.  Per-action command line parameters take prece-
       dence 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 codebase.

	   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/ direc-
	   tory.  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 pro-
	   cessed 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 com-
	   press the tarball using GZIP compression.

	   By default, this action will use the "Archive::Tar" module. How-
	   ever, 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 MAN-
	   IFEST 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_ver-
	   sion" (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.

       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, ver-
	   sion, abstract, prerequisites, license, and various other data
	   about the distribution.  This file is created as META.yml in YAML
	   format.  It is recommended that the "YAML" module be installed to
	   create it.  If the "YAML" module is not installed, an internal
	   module supplied with Module::Build will be used to write the
	   META.yml file, and this will most likely be fine.

	   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 at
	   <http://module-build.sourceforge.net/META-spec-current.html>

       distsign
	   [version 0.16]

	   Uses "Module::Signature" to create a SIGNATURE file for your dis-
	   tribution, and adds the SIGNATURE file to the distribution’s MANI-
	   FEST.

       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.

       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 val-
	   ues 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 "ExtU-
	   tils::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 confus-
	   ing situation indeed.

       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 distribu-
	   tion 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 any-
	   thing.

       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" instal-
	   lation 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 prerequsites
	   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 $(INSTALLARCH-
	   LIB)/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 "real-
	   clean" 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 ver-
	   sions 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 MANI-
	   FEST.SKIP file (See manifest for details)

       test
	   [version 0.01]

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

	   If you want tests to be ’verbose’, i.e. show details of test exe-
	   cution rather than just summary information, pass the argument
	   "verbose=1".

	   If you want to run tests under the perl debugger, pass the argu-
	   ment "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" for-
	   mat 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
	   [verion 0.2807]

	   [Note: the ’testall’ action and the code snippets below are cur-
	   rently in alpha stage, see
	   "http://www.nntp.perl.org/group/perl.mod-
	   ule.build/2007/03/msg584.html" ]

	   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 pro-
	   duces "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
	   "versionlib" 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 respec-
       tive 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.

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

       verbose
	   Display extra information about the Build on output.

       allow_mb_mismatch
	   Suppresses the check upon startup that the version of Mod-
	   ule::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).  Use with caution.

       Default Options File (.modulebuildrc)

       [version 0.28]

       When Module::Build starts up, it will look first for a file,
       $ENV{HOME}/.modulebuildrc.  If it’s not found there, it will look in
       the the .modulebuildrc file in the directories referred to by the
       environment variables "HOMEDRIVE" + "HOMEDIR", "USERPROFILE", "APP-
       DATA", "WINDIR", "SYS$LOGIN".  If the file exists, the options speci-
       fied there will be used as defaults, as if they were typed on the com-
       mand 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 whites-
       pace at the beginning of each continued line.  Anything following a
       hash mark ("#") is considered a comment, and is stripped before pars-
       ing.  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

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

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 compil-
	   ing 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 when-
	   ever 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 gener-
	   ated 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 "bindoc" above, but applies to html documents.

       Four other parameters let you control various aspects of how installa-
       tion 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	installsitebin	    installvendorbin
	     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 some-
	   thing 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 - unfor-
	   tunately there’s no such thing as "installsitescript" or "install-
	   vendorscript" entry in "Config.pm", so we use the "installsitebin"
	   and "installvendorbin" entries to at least get the general loca-
	   tion right.	In the future, if "Config.pm" adds some more appro-
	   priate 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 supply-
	   ing 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" parame-
	   ter 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 sys-
	   tem - 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 pack-
	   age 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 argu-
	   ment.  "prefix" should be used when you wish Module::Build to
	   install your modules, documentation and scripts in the same place
	   ExtUtils::MakeMaker does.

	   The following are equivalent.

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

	   Because of the very 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.

	   If you do not need to retain compatibility with ExtUtils::Make-
	   Maker or are starting a fresh Perl installation we recommand you
	   use "install_base" instead (and "INSTALL_BASE" in ExtUtils::Make-
	   Maker).  See "Instaling in the same location as ExtUtils::Make-
	   Maker" 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 distribu-
	       tion, 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 mod-
	   ify a string containing the Makefile text for the particular tar-
	   get.	 Since these strings aren’t documented, and can’t be docu-
	   mented (they take on different values depending on the platform,
	   version of perl, version of MakeMaker, etc.), you have no guaran-
	   tee 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.  "Mod-
	   ule::Build" is an entirely separate package so that I can work on
	   it all I want, without worrying about backward compatibility.

       ·   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 stupid little ".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 Subversion repos-
       itory at <https://svn.perl.org/modules/Module-Build/trunk/>

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, Mod-
       ule::Build::API, ExtUtils::MakeMaker, YAML

       META.yml Specification: <http://module-build.source-
       forge.net/META-spec-current.html>

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

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



perl v5.8.8			  2009-05-27		     Module::Build(3)