3 # This module doesn't do much of anything itself, it inherits from the
4 # modules that do the real work. The only real thing it has to do is
5 # figure out which OS-specific module to pull in. Many of the
6 # OS-specific modules don't do anything either - most of the work is
7 # done in Module::Build::Base.
12 use File::Basename ();
14 use Module::Build::Base;
16 use vars qw($VERSION @ISA);
17 @ISA = qw(Module::Build::Base);
19 $VERSION = eval $VERSION;
21 # Okay, this is the brute-force method of finding out what kind of
22 # platform we're on. I don't know of a systematic way. These values
23 # came from the latest (bleadperl) perlport.pod.
72 # Inserts the given module into the @ISA hierarchy between
73 # Module::Build and its immediate parent
74 sub _interpose_module {
75 my ($self, $mod) = @_;
81 while (@{"${top_class}::ISA"}) {
82 last if ${"${top_class}::ISA"}[0] eq $ISA[0];
83 $top_class = ${"${top_class}::ISA"}[0];
86 @{"${top_class}::ISA"} = @ISA;
90 if (grep {-e File::Spec->catfile($_, qw(Module Build Platform), $^O) . '.pm'} @INC) {
91 __PACKAGE__->_interpose_module("Module::Build::Platform::$^O");
93 } elsif (exists $OSTYPES{$^O}) {
94 __PACKAGE__->_interpose_module("Module::Build::Platform::$OSTYPES{$^O}");
97 warn "Unknown OS type '$^O' - using default settings\n";
100 sub os_type { $OSTYPES{$^O} }
102 sub is_vmsish { return ((os_type() || '') eq 'VMS') }
103 sub is_windowsish { return ((os_type() || '') eq 'Windows') }
104 sub is_unixish { return ((os_type() || '') eq 'Unix') }
113 Module::Build - Build and install Perl modules
118 Standard process for building & installing modules:
125 Or, if you're on a platform (like DOS or Windows) that doesn't require
126 the "./" notation, you can do this:
136 C<Module::Build> is a system for building, testing, and installing
137 Perl modules. It is meant to be an alternative to
138 C<ExtUtils::MakeMaker>. Developers may alter the behavior of the
139 module through subclassing in a much more straightforward way than
140 with C<MakeMaker>. It also does not require a C<make> on your system
141 - most of the C<Module::Build> code is pure-perl and written in a very
142 cross-platform way. In fact, you don't even need a shell, so even
143 platforms like MacOS (traditional) can use it fairly easily. Its only
144 prerequisites are modules that are included with perl 5.6.0, and it
145 works fine on perl 5.005 if you can install a few additional modules.
147 See L<"MOTIVATIONS"> for more comparisons between C<ExtUtils::MakeMaker>
148 and C<Module::Build>.
150 To install C<Module::Build>, and any other module that uses
151 C<Module::Build> for its installation process, do the following:
153 perl Build.PL # 'Build.PL' script creates the 'Build' script
154 ./Build # Need ./ to ensure we're using this "Build" script
155 ./Build test # and not another one that happens to be in the PATH
158 This illustrates initial configuration and the running of three
159 'actions'. In this case the actions run are 'build' (the default
160 action), 'test', and 'install'. Other actions defined so far include:
168 distcheck pure_install
178 install versioninstall
181 You can run the 'help' action for a complete list of actions.
184 =head1 GUIDE TO DOCUMENTATION
186 The documentation for C<Module::Build> is broken up into three sections:
190 =item General Usage (L<Module::Build>)
192 This is the document you are currently reading. It describes basic
193 usage and background information. Its main purpose is to assist the
194 user who wants to learn how to invoke and control C<Module::Build>
195 scripts at the command line.
197 =item Authoring Reference (L<Module::Build::Authoring>)
199 This document describes the structure and organization of
200 C<Module::Build>, and the relevant concepts needed by authors who are
201 writing F<Build.PL> scripts for a distribution or controlling
202 C<Module::Build> processes programmatically.
204 =item API Reference (L<Module::Build::API>)
206 This is a reference to the C<Module::Build> API.
208 =item Cookbook (L<Module::Build::Cookbook>)
210 This document demonstrates how to accomplish many common tasks. It
211 covers general command line usage and authoring of F<Build.PL>
212 scripts. Includes working examples.
219 There are some general principles at work here. First, each task when
220 building a module is called an "action". These actions are listed
221 above; they correspond to the building, testing, installing,
222 packaging, etc., tasks.
224 Second, arguments are processed in a very systematic way. Arguments
225 are always key=value pairs. They may be specified at C<perl Build.PL>
226 time (i.e. C<perl Build.PL destdir=/my/secret/place>), in which case
227 their values last for the lifetime of the C<Build> script. They may
228 also be specified when executing a particular action (i.e.
229 C<Build test verbose=1>), in which case their values last only for the
230 lifetime of that command. Per-action command line parameters take
231 precedence over parameters specified at C<perl Build.PL> time.
233 The build process also relies heavily on the C<Config.pm> module.
234 If the user wishes to override any of the
235 values in C<Config.pm>, she may specify them like so:
237 perl Build.PL --config cc=gcc --config ld=gcc
239 The following build actions are provided by default.
247 If you run the C<Build> script without any arguments, it runs the
248 C<build> action, which in turn runs the C<code> and C<docs> actions.
250 This is analogous to the MakeMaker 'make all' target.
256 This action will clean up any files that the build process may have
257 created, including the C<blib/> directory (but not including the
258 C<_build/> directory and the C<Build> script itself).
264 This action builds your codebase.
266 By default it just creates a C<blib/> directory and copies any C<.pm>
267 and C<.pod> files from your C<lib/> directory into the C<blib/>
268 directory. It also compiles any C<.xs> files from C<lib/> and places
269 them in C<blib/>. Of course, you need a working C compiler (probably
270 the same one that built perl itself) for the compilation to work
273 The C<code> action also runs any C<.PL> files in your F<lib/>
274 directory. Typically these create other files, named the same but
275 without the C<.PL> ending. For example, a file F<lib/Foo/Bar.pm.PL>
276 could create the file F<lib/Foo/Bar.pm>. The C<.PL> files are
277 processed first, so any C<.pm> files (or other kinds that we deal
278 with) will get copied correctly.
290 This action will compare the files about to be installed with their
291 installed counterparts. For .pm and .pod files, a diff will be shown
292 (this currently requires a 'diff' program to be in your PATH). For
293 other files like compiled binary files, we simply report whether they
296 A C<flags> parameter may be passed to the action, which will be passed
297 to the 'diff' program. Consult your 'diff' documentation for the
298 parameters it will accept - a good one is C<-u>:
300 ./Build diff flags=-u
306 This action is helpful for module authors who want to package up their
307 module for source distribution through a medium like CPAN. It will create a
308 tarball of the files listed in F<MANIFEST> and compress the tarball using
311 By default, this action will use the external C<tar> and C<gzip>
312 executables on Unix-like platforms, and the C<Archive::Tar> module
313 elsewhere. However, you can force it to use whatever executable you
314 want by supplying an explicit C<tar> (and optional C<gzip>) parameter:
316 ./Build dist --tar C:\path\to\tar.exe --gzip C:\path\to\zip.exe
322 Reports which files are in the build directory but not in the
323 F<MANIFEST> file, and vice versa. (See L<manifest> for details.)
329 Performs the 'realclean' action and then the 'distcheck' action.
335 Creates a "distribution directory" named C<$dist_name-$dist_version>
336 (if that directory already exists, it will be removed first), then
337 copies all the files listed in the F<MANIFEST> file to that directory.
338 This directory is what the distribution tarball is created from.
344 Creates the F<META.yml> file that describes the distribution.
346 F<META.yml> is a file containing various bits of "metadata" about the
347 distribution. The metadata includes the distribution name, version,
348 abstract, prerequisites, license, and various other data about the
349 distribution. This file is created as F<META.yml> in YAML format.
350 It is recommended that the C<YAML> module be installed to create it.
351 If the C<YAML> module is not installed, an internal module supplied
352 with Module::Build will be used to write the META.yml file, and this
353 will most likely be fine.
355 F<META.yml> file must also be listed in F<MANIFEST> - if it's not, a
356 warning will be issued.
358 The current version of the F<META.yml> specification can be found at
359 L<http://module-build.sourceforge.net/META-spec-current.html>
365 Uses C<Module::Signature> to create a SIGNATURE file for your
366 distribution, and adds the SIGNATURE file to the distribution's
373 Performs the 'distdir' action, then switches into that directory and
374 runs a C<perl Build.PL>, followed by the 'build' and 'test' actions in
381 This will generate documentation (e.g. Unix man pages and html
382 documents) for any installable items under B<blib/> that
383 contain POD. If there are no C<bindoc> or C<libdoc> installation
384 targets defined (as will be the case on systems that don't support
385 Unix manpages) no action is taken for manpages. If there are no
386 C<binhtml> or C<libhtml> installation targets defined no action is
387 taken for html documents.
393 This is just like the C<install> action, but it won't actually do
394 anything, it will just report what it I<would> have done if you had
395 actually run the C<install> action.
401 This action will simply print out a message that is meant to help you
402 use the build process. It will show you a list of available build
405 With an optional argument specifying an action name (e.g. C<Build help
406 test>), the 'help' action will show you any POD documentation it can
407 find for that action.
413 This will generate HTML documentation for any binary or library files
414 under B<blib/> that contain POD. The HTML documentation will only be
415 installed if the install paths can be determined from values in
416 C<Config.pm>. You can also supply or override install paths on the
417 command line by specifying C<install_path> values for the C<binhtml>
418 and/or C<libhtml> installation targets.
424 This action will use C<ExtUtils::Install> to install the files from
425 C<blib/> into the system. See L<"INSTALL PATHS">
426 for details about how Module::Build determines where to install
427 things, and how to influence this process.
429 If you want the installation process to look around in C<@INC> for
430 other versions of the stuff you're installing and try to delete it,
431 you can use the C<uninst> parameter, which tells C<ExtUtils::Install> to
434 ./Build install uninst=1
436 This can be a good idea, as it helps prevent multiple versions of a
437 module from being present on your system, which can be a confusing
444 This is an action intended for use by module authors, not people
445 installing modules. It will bring the F<MANIFEST> up to date with the
446 files currently present in the distribution. You may use a
447 F<MANIFEST.SKIP> file to exclude certain files or directories from
448 inclusion in the F<MANIFEST>. F<MANIFEST.SKIP> should contain a bunch
449 of regular expressions, one per line. If a file in the distribution
450 directory matches any of the regular expressions, it won't be included
453 The following is a reasonable F<MANIFEST.SKIP> starting point, you can
454 add your own stuff to it:
464 See the L<distcheck> and L<skipcheck> actions if you want to find out
465 what the C<manifest> action would do, without actually doing anything.
471 This will generate man pages for any binary or library files under
472 B<blib/> that contain POD. The man pages will only be installed if the
473 install paths can be determined from values in C<Config.pm>. You can
474 also supply or override install paths by specifying there values on
475 the command line with the C<bindoc> and C<libdoc> installation
482 Generates a PAR binary distribution for use with L<PAR> or L<PAR::Dist>.
484 It requires that the PAR::Dist module (version 0.17 and up) is
485 installed on your system.
491 Build a PPD file for your distribution.
493 This action takes an optional argument C<codebase> which is used in
494 the generated ppd file to specify the (usually relative) URL of the
495 distribution. By default, this value is the distribution name without
496 any path information.
500 ./Build ppd --codebase "MSWin32-x86-multi-thread/Module-Build-0.21.tar.gz"
506 Generates a PPM binary distribution and a PPD description file. This
507 action also invokes the 'ppd' action, so it can accept the same
508 C<codebase> argument described under that action.
510 This uses the same mechanism as the C<dist> action to tar & zip its
511 output, so you can supply C<tar> and/or C<gzip> parameters to affect
518 This action prints out a list of all prerequisites, the versions required, and
519 the versions actually installed. This can be useful for reviewing the
520 configuration of your system prior to a build, or when compiling data to send
527 This action is identical to the C<install> action. In the future,
528 though, when C<install> starts writing to the file
529 F<$(INSTALLARCHLIB)/perllocal.pod>, C<pure_install> won't, and that
530 will be the only difference between them.
536 This action is just like the C<clean> action, but also removes the
537 C<_build> directory and the C<Build> script. If you run the
538 C<realclean> action, you are essentially starting over, so you will
539 have to re-create the C<Build> script again.
545 This is just like the C<test> action, but doesn't actually build the
546 distribution first, and doesn't add F<blib/> to the load path, and
547 therefore will test against a I<previously> installed version of the
548 distribution. This can be used to verify that a certain installed
549 distribution still works, or to see whether newer versions of a
550 distribution still pass the old regression tests, and so on.
556 Reports which files are skipped due to the entries in the
557 F<MANIFEST.SKIP> file (See L<manifest> for details)
563 This will use C<Test::Harness> or C<TAP::Harness> to run any regression
564 tests and report their results. Tests can be defined in the standard
565 places: a file called C<test.pl> in the top-level directory, or several
566 files ending with C<.t> in a C<t/> directory.
568 If you want tests to be 'verbose', i.e. show details of test execution
569 rather than just summary information, pass the argument C<verbose=1>.
571 If you want to run tests under the perl debugger, pass the argument
574 If you want to have Module::Build find test files with different file
575 name extensions, pass the C<test_file_exts> argument with an array
576 of extensions, such as C<[qw( .t .s .z )]>.
578 If you want test to be run by C<TAP::Harness>, rather than C<Test::Harness>,
579 pass the argument C<tap_harness_args> as an array reference of arguments to
580 pass to the TAP::Harness constructor.
582 In addition, if a file called C<visual.pl> exists in the top-level
583 directory, this file will be executed as a Perl script and its output
584 will be shown to the user. This is a good place to put speed tests or
585 other tests that don't use the C<Test::Harness> format for output.
587 To override the choice of tests to run, you may pass a C<test_files>
588 argument whose value is a whitespace-separated list of test scripts to
589 run. This is especially useful in development, when you only want to
590 run a single test to see whether you've squashed a certain bug yet:
592 ./Build test --test_files t/something_failing.t
594 You may also pass several C<test_files> arguments separately:
596 ./Build test --test_files t/one.t --test_files t/two.t
598 or use a C<glob()>-style pattern:
600 ./Build test --test_files 't/01-*.t'
606 [Note: the 'testall' action and the code snippets below are currently
608 L<"http://www.nntp.perl.org/group/perl.module.build/2007/03/msg584.html"> ]
610 Runs the C<test> action plus each of the C<test$type> actions defined by
611 the keys of the C<test_types> parameter.
613 Currently, you need to define the ACTION_test$type method yourself and
614 enumerate them in the test_types parameter.
616 my $mb = Module::Build->subclass(
618 sub ACTION_testspecial { shift->generic_test(type => 'special'); }
619 sub ACTION_testauthor { shift->generic_test(type => 'author'); }
625 author => ['.at', '.pt' ],
633 Runs the C<test> action using C<Devel::Cover>, generating a
634 code-coverage report showing which parts of the code were actually
635 exercised during the tests.
637 To pass options to C<Devel::Cover>, set the C<$DEVEL_COVER_OPTIONS>
638 environment variable:
640 DEVEL_COVER_OPTIONS=-ignore,Build ./Build testcover
646 This is a synonym for the 'test' action with the C<debugger=1>
653 This checks all the files described in the C<docs> action and
654 produces C<Test::Harness>-style output. If you are a module author,
655 this is useful to run before creating a new release.
657 =item testpodcoverage
661 This checks the pod coverage of the distribution and
662 produces C<Test::Harness>-style output. If you are a module author,
663 this is useful to run before creating a new release.
669 ** Note: since C<only.pm> is so new, and since we just recently added
670 support for it here too, this feature is to be considered
673 If you have the C<only.pm> module installed on your system, you can
674 use this action to install a module into the version-specific library
675 trees. This means that you can have several versions of the same
676 module installed and C<use> a specific one like this:
678 use only MyModule => 0.55;
680 To override the default installation libraries in C<only::config>,
681 specify the C<versionlib> parameter when you run the C<Build.PL> script:
683 perl Build.PL --versionlib /my/version/place/
685 To override which version the module is installed as, specify the
686 C<versionlib> parameter when you run the C<Build.PL> script:
688 perl Build.PL --version 0.50
690 See the C<only.pm> documentation for more information on
691 version-specific installs.
698 =head2 Command Line Options
700 The following options can be used during any invocation of C<Build.PL>
701 or the Build script, during any action. For information on other
702 options specific to an action, see the documentation for the
705 NOTE: There is some preliminary support for options to use the more
706 familiar long option style. Most options can be preceded with the
707 C<--> long option prefix, and the underscores changed to dashes
708 (e.g. --use-rcfile). Additionally, the argument to boolean options is
709 optional, and boolean options can be negated by prefixing them with
710 'no' or 'no-' (e.g. --noverbose or --no-verbose).
716 Suppress informative messages on output.
720 Load the F<~/.modulebuildrc> option file. This option can be set to
721 false to prevent the custom resource file from being loaded.
725 Display extra information about the Build on output.
727 =item allow_mb_mismatch
729 Suppresses the check upon startup that the version of Module::Build
730 we're now running under is the same version that was initially invoked
731 when building the distribution (i.e. when the C<Build.PL> script was
732 first run). Use with caution.
737 =head2 Default Options File (F<.modulebuildrc>)
741 When Module::Build starts up, it will look first for a file,
742 F<$ENV{HOME}/.modulebuildrc>. If it's not found there, it will look
743 in the the F<.modulebuildrc> file in the directories referred to by
744 the environment variables C<HOMEDRIVE> + C<HOMEDIR>, C<USERPROFILE>,
745 C<APPDATA>, C<WINDIR>, C<SYS$LOGIN>. If the file exists, the options
746 specified there will be used as defaults, as if they were typed on the
747 command line. The defaults can be overridden by specifying new values
750 The action name must come at the beginning of the line, followed by any
751 amount of whitespace and then the options. Options are given the same
752 as they would be on the command line. They can be separated by any
753 amount of whitespace, including newlines, as long there is whitespace at
754 the beginning of each continued line. Anything following a hash mark (C<#>)
755 is considered a comment, and is stripped before parsing. If more than
756 one line begins with the same action name, those lines are merged into
759 Besides the regular actions, there are two special pseudo-actions: the
760 key C<*> (asterisk) denotes any global options that should be applied
761 to all actions, and the key 'Build_PL' specifies options to be applied
762 when you invoke C<perl Build.PL>.
764 * verbose=1 # global options
766 install --install_base /home/ken
767 --install_path html=/home/ken/docs/html
769 If you wish to locate your resource file in a different location, you
770 can set the environment variable 'MODULEBUILDRC' to the complete
771 absolute path of the file containing your options.
778 When you invoke Module::Build's C<build> action, it needs to figure
779 out where to install things. The nutshell version of how this works
780 is that default installation locations are determined from
781 F<Config.pm>, and they may be overridden by using the C<install_path>
782 parameter. An C<install_base> parameter lets you specify an
783 alternative installation root like F</home/foo>, and a C<destdir> lets
784 you specify a temporary installation directory like F</tmp/install> in
785 case you want to create bundled-up installable packages.
787 Natively, Module::Build provides default installation locations for
788 the following types of installable items:
794 Usually pure-Perl module files ending in F<.pm>.
798 "Architecture-dependent" module files, usually produced by compiling
799 XS, Inline, or similar code.
803 Programs written in pure Perl. In order to improve reuse, try to make
804 these as small as possible - put the code into modules whenever
809 "Architecture-dependent" executable programs, i.e. compiled C code or
810 something. Pretty rare to see this in a perl distribution, but it
815 Documentation for the stuff in C<script> and C<bin>. Usually
816 generated from the POD in those files. Under Unix, these are manual
817 pages belonging to the 'man1' category.
821 Documentation for the stuff in C<lib> and C<arch>. This is usually
822 generated from the POD in F<.pm> files. Under Unix, these are manual
823 pages belonging to the 'man3' category.
827 This is the same as C<bindoc> above, but applies to html documents.
831 This is the same as C<bindoc> above, but applies to html documents.
835 Four other parameters let you control various aspects of how
836 installation paths are determined:
842 The default destinations for these installable things come from
843 entries in your system's C<Config.pm>. You can select from three
844 different sets of default locations by setting the C<installdirs>
845 parameter as follows:
847 'installdirs' set to:
850 uses the following defaults from Config.pm:
852 lib => installprivlib installsitelib installvendorlib
853 arch => installarchlib installsitearch installvendorarch
854 script => installscript installsitebin installvendorbin
855 bin => installbin installsitebin installvendorbin
856 bindoc => installman1dir installsiteman1dir installvendorman1dir
857 libdoc => installman3dir installsiteman3dir installvendorman3dir
858 binhtml => installhtml1dir installsitehtml1dir installvendorhtml1dir [*]
859 libhtml => installhtml3dir installsitehtml3dir installvendorhtml3dir [*]
861 * Under some OS (eg. MSWin32) the destination for html documents is
862 determined by the C<Config.pm> entry C<installhtmldir>.
864 The default value of C<installdirs> is "site". If you're creating
865 vendor distributions of module packages, you may want to do something
868 perl Build.PL --installdirs vendor
872 ./Build install --installdirs vendor
874 If you're installing an updated version of a module that was included
875 with perl itself (i.e. a "core module"), then you may set
876 C<installdirs> to "core" to overwrite the module in its present
879 (Note that the 'script' line is different from MakeMaker -
880 unfortunately there's no such thing as "installsitescript" or
881 "installvendorscript" entry in C<Config.pm>, so we use the
882 "installsitebin" and "installvendorbin" entries to at least get the
883 general location right. In the future, if C<Config.pm> adds some more
884 appropriate entries, we'll start using those.)
888 Once the defaults have been set, you can override them.
890 On the command line, that would look like this:
892 perl Build.PL --install_path lib=/foo/lib --install_path arch=/foo/lib/arch
896 ./Build install --install_path lib=/foo/lib --install_path arch=/foo/lib/arch
900 You can also set the whole bunch of installation paths by supplying the
901 C<install_base> parameter to point to a directory on your system. For
902 instance, if you set C<install_base> to "/home/ken" on a Linux
903 system, you'll install as follows:
905 lib => /home/ken/lib/perl5
906 arch => /home/ken/lib/perl5/i386-linux
907 script => /home/ken/bin
909 bindoc => /home/ken/man/man1
910 libdoc => /home/ken/man/man3
911 binhtml => /home/ken/html
912 libhtml => /home/ken/html
914 Note that this is I<different> from how MakeMaker's C<PREFIX>
915 parameter works. C<install_base> just gives you a default layout under the
916 directory you specify, which may have little to do with the
917 C<installdirs=site> layout.
919 The exact layout under the directory you specify may vary by system -
920 we try to do the "sensible" thing on each platform.
924 If you want to install everything into a temporary directory first
925 (for instance, if you want to create a directory tree that a package
926 manager like C<rpm> or C<dpkg> could create a package from), you can
927 use the C<destdir> parameter:
929 perl Build.PL --destdir /tmp/foo
933 ./Build install --destdir /tmp/foo
935 This will effectively install to "/tmp/foo/$sitelib",
936 "/tmp/foo/$sitearch", and the like, except that it will use
937 C<File::Spec> to make the pathnames work correctly on whatever
938 platform you're installing on.
942 Provided for compatibility with ExtUtils::MakeMaker's PREFIX argument.
943 C<prefix> should be used when you wish Module::Build to install your
944 modules, documentation and scripts in the same place
945 ExtUtils::MakeMaker does.
947 The following are equivalent.
949 perl Build.PL --prefix /tmp/foo
950 perl Makefile.PL PREFIX=/tmp/foo
952 Because of the very complex nature of the prefixification logic, the
953 behavior of PREFIX in MakeMaker has changed subtly over time.
954 Module::Build's --prefix logic is equivalent to the PREFIX logic found
955 in ExtUtils::MakeMaker 6.30.
957 If you do not need to retain compatibility with ExtUtils::MakeMaker or
958 are starting a fresh Perl installation we recommand you use
959 C<install_base> instead (and C<INSTALL_BASE> in ExtUtils::MakeMaker).
960 See L<Module::Build::Cookbook/Instaling in the same location as
961 ExtUtils::MakeMaker> for further information.
969 There are several reasons I wanted to start over, and not just fix
970 what I didn't like about MakeMaker:
976 I don't like the core idea of MakeMaker, namely that C<make> should be
977 involved in the build process. Here are my reasons:
983 When a person is installing a Perl module, what can you assume about
984 their environment? Can you assume they have C<make>? No, but you can
985 assume they have some version of Perl.
989 When a person is writing a Perl module for intended distribution, can
990 you assume that they know how to build a Makefile, so they can
991 customize their build process? No, but you can assume they know Perl,
992 and could customize that way.
996 For years, these things have been a barrier to people getting the
997 build/install process to do what they want.
1001 There are several architectural decisions in MakeMaker that make it
1002 very difficult to customize its behavior. For instance, when using
1003 MakeMaker you do C<use ExtUtils::MakeMaker>, but the object created in
1004 C<WriteMakefile()> is actually blessed into a package name that's
1005 created on the fly, so you can't simply subclass
1006 C<ExtUtils::MakeMaker>. There is a workaround C<MY> package that lets
1007 you override certain MakeMaker methods, but only certain explicitly
1008 preselected (by MakeMaker) methods can be overridden. Also, the method
1009 of customization is very crude: you have to modify a string containing
1010 the Makefile text for the particular target. Since these strings
1011 aren't documented, and I<can't> be documented (they take on different
1012 values depending on the platform, version of perl, version of
1013 MakeMaker, etc.), you have no guarantee that your modifications will
1014 work on someone else's machine or after an upgrade of MakeMaker or
1019 It is risky to make major changes to MakeMaker, since it does so many
1020 things, is so important, and generally works. C<Module::Build> is an
1021 entirely separate package so that I can work on it all I want, without
1022 worrying about backward compatibility.
1026 Finally, Perl is said to be a language for system administration.
1027 Could it really be the case that Perl isn't up to the task of building
1028 and installing software? Even if that software is a bunch of stupid
1029 little C<.pm> files that just need to be copied from one place to
1030 another? My sense was that we could design a system to accomplish
1031 this in a flexible, extensible, and friendly manner. Or die trying.
1038 The current method of relying on time stamps to determine whether a
1039 derived file is out of date isn't likely to scale well, since it
1040 requires tracing all dependencies backward, it runs into problems on
1041 NFS, and it's just generally flimsy. It would be better to use an MD5
1042 signature or the like, if available. See C<cons> for an example.
1044 - append to perllocal.pod
1045 - add a 'plugin' functionality
1050 Ken Williams <kwilliams@cpan.org>
1052 Development questions, bug reports, and patches should be sent to the
1053 Module-Build mailing list at <module-build@perl.org>.
1055 Bug reports are also welcome at
1056 <http://rt.cpan.org/NoAuth/Bugs.html?Dist=Module-Build>.
1058 The latest development version is available from the Subversion
1059 repository at <https://svn.perl.org/modules/Module-Build/trunk/>
1064 Copyright (c) 2001-2006 Ken Williams. All rights reserved.
1066 This library is free software; you can redistribute it and/or
1067 modify it under the same terms as Perl itself.
1072 perl(1), L<Module::Build::Cookbook>, L<Module::Build::Authoring>,
1073 L<Module::Build::API>, L<ExtUtils::MakeMaker>, L<YAML>
1075 F<META.yml> Specification:
1076 L<http://module-build.sourceforge.net/META-spec-current.html>
1078 L<http://www.dsmit.com/cons/>
1080 L<http://search.cpan.org/dist/PerlBuildSystem/>