ExtUtils::MakeMaker::FAQ(3p) Perl Programmers Reference Guide

ExtUtils::MakeMaker::FAQ(3p) Perl Programmers Reference Guide #

ExtUtils::MakeMaker::FAQ(3p) Perl Programmers Reference Guide

NNAAMMEE #

 ExtUtils::MakeMaker::FAQ - Frequently Asked Questions About MakeMaker

DDEESSCCRRIIPPTTIIOONN #

 FAQs, tricks and tips for ExtUtils::MakeMaker.

MMoodduullee IInnssttaallllaattiioonn How do I install a module into my home directory? If you’re not the Perl administrator you probably don’t have permission to install a module to its default location. Ways of handling this with a lloott less manual effort on your part are perlbrew and local::lib.

     Otherwise, you can install it for your own use into your home
     directory like so:

         # Non-unix folks, replace ~ with /path/to/your/home/dir
         perl Makefile.PL INSTALL_BASE=~

     This will put modules into _~_/_l_i_b_/_p_e_r_l_5, man pages into _~_/_m_a_n and
     programs into _~_/_b_i_n.

     To ensure your Perl programs can see these newly installed modules,
     set your "PERL5LIB" environment variable to _~_/_l_i_b_/_p_e_r_l_5 or tell each
     of your programs to look in that directory with the following:

         use lib "$ENV{HOME}/lib/perl5";

     or if $ENV{HOME} isn't set and you don't want to set it for some
     reason, do it the long way.

         use lib "/path/to/your/home/dir/lib/perl5";

 How do I get MakeMaker and Module::Build to install to the same place?
     Module::Build, as of 0.28, supports two ways to install to the same
     location as MakeMaker.

     We highly recommend the install_base method, its the simplest and
     most closely approximates the expected behavior of an installation
     prefix.

     1) Use INSTALL_BASE / "--install_base"

     MakeMaker (as of 6.31) and Module::Build (as of 0.28) both can
     install to the same locations using the "install_base" concept.  See
     "INSTALL_BASE" in ExtUtils::MakeMaker for details.  To get MM and MB
     to install to the same location simply set INSTALL_BASE in MM and
     "--install_base" in MB to the same location.

         perl Makefile.PL INSTALL_BASE=/whatever
         perl Build.PL    --install_base /whatever

     This works most like other language's behavior when you specify a
     prefix.  We recommend this method.

     2) Use PREFIX / "--prefix"

     Module::Build 0.28 added support for "--prefix" which works like
     MakeMaker's PREFIX.

         perl Makefile.PL PREFIX=/whatever
         perl Build.PL    --prefix /whatever

     We highly discourage this method.  It should only be used if you know
     what you're doing and specifically need the PREFIX behavior.  The
     PREFIX algorithm is complicated and focused on matching the system
     installation.

 How do I keep from installing man pages?
     Recent versions of MakeMaker will only install man pages on Unix-like
     operating systems by default. To generate manpages on non-Unix
     operating systems, make the "manifypods" target.

     For an individual module:

             perl Makefile.PL INSTALLMAN1DIR=none INSTALLMAN3DIR=none

     If you want to suppress man page installation for all modules you
     have to reconfigure Perl and tell it 'none' when it asks where to
     install man pages.

 How do I use a module without installing it?
     Two ways.  One is to build the module normally...

             perl Makefile.PL
             make
             make test

     ...and then use blib to point Perl at the built but uninstalled
     module:

             perl -Mblib script.pl
             perl -Mblib -e '...'

     The other is to install the module in a temporary location.

             perl Makefile.PL INSTALL_BASE=~/tmp
             make
             make test
             make install

     And then set PERL5LIB to _~_/_t_m_p_/_l_i_b_/_p_e_r_l_5.  This works well when you
     have multiple modules to work with.  It also ensures that the module
     goes through its full installation process which may modify it.
     Again, local::lib may assist you here.

 How can I organize tests into subdirectories and have them run?
     Let's take the following test directory structure:

         t/foo/sometest.t
         t/bar/othertest.t
         t/bar/baz/anothertest.t

     Now, inside of the "WriteMakeFile()" function in your _M_a_k_e_f_i_l_e_._P_L,
     specify where your tests are located with the "test" directive:

         test => {TESTS => 't/*.t t/*/*.t t/*/*/*.t'}

     The first entry in the string will run all tests in the top-level _t_/
     directory. The second will run all test files located in any
     subdirectory under _t_/. The third, runs all test files within any
     subdirectory within any other subdirectory located under _t_/.

     Note that you do not have to use wildcards. You can specify
     explicitly which subdirectories to run tests in:

         test => {TESTS => 't/*.t t/foo/*.t t/bar/baz/*.t'}

 PREFIX vs INSTALL_BASE from Module::Build::Cookbook
     The behavior of PREFIX is complicated and depends closely on how your
     Perl is configured. The resulting installation locations will vary
     from machine to machine and even different installations of Perl on
     the same machine.  Because of this, its difficult to document where
     prefix will place your modules.

     In contrast, INSTALL_BASE has predictable, easy to explain
     installation locations.  Now that Module::Build and MakeMaker both
     have INSTALL_BASE there is little reason to use PREFIX other than to
     preserve your existing installation locations. If you are starting a
     fresh Perl installation we encourage you to use INSTALL_BASE. If you
     have an existing installation installed via PREFIX, consider moving
     it to an installation structure matching INSTALL_BASE and using that
     instead.

 Generating *.pm files with substitutions eg of $VERSION
     If you want to configure your module files for local conditions, or
     to automatically insert a version number, you can use EUMM's
     "PL_FILES" capability, where it will automatically run each _*_._P_L it
     finds to generate its basename. For instance:

         # Makefile.PL:
         require 'common.pl';
         my $version = get_version();
         my @pms = qw(Foo.pm);
         WriteMakefile(
           NAME => 'Foo',
           VERSION => $version,
           PM => { map { ($_ => "\$(INST_LIB)/$_") } @pms },
           clean => { FILES => join ' ', @pms },
         );

         # common.pl:
         sub get_version { '0.04' }
         sub process { my $v = get_version(); s/__VERSION__/$v/g; }
         1;

         # Foo.pm.PL:
         require 'common.pl';
         $_ = join '', <DATA>;
         process();
         my $file = shift;
         open my $fh, '>', $file or die "$file: $!";
         print $fh $_;

DATA #

         package Foo;
         our $VERSION = '__VERSION__';
         1;

     You may notice that "PL_FILES" is not specified above, since the
     default of mapping each .PL file to its basename works well.

     If the generated module were architecture-specific, you could replace
     "$(INST_LIB)" above with "$(INST_ARCHLIB)", although if you locate
     modules under _l_i_b, that would involve ensuring any "lib/" in front of
     the module location were removed.

CCoommmmoonn eerrrroorrss aanndd pprroobblleemmss “No rule to make target /usr/lib/perl5/CORE/config.h', needed by Makefile’” Just what it says, you’re missing that file. MakeMaker uses it to determine if perl has been rebuilt since the Makefile was made. It’s a bit of a bug that it halts installation.

     Some operating systems don't ship the CORE directory with their base
     perl install.  To solve the problem, you likely need to install a
     perl development package such as perl-devel (CentOS, Fedora and other
     Redhat systems) or perl (Ubuntu and other Debian systems).

PPhhiilloossoopphhyy aanndd HHiissttoorryy Why not just use ? Why did MakeMaker reinvent the build configuration wheel? Why not just use autoconf or automake or ppm or Ant or …

     There are many reasons, but the major one is cross-platform
     compatibility.

     Perl is one of the most ported pieces of software ever.  It works on
     operating systems I've never even heard of (see perlport for
     details).  It needs a build tool that can work on all those platforms
     and with any wacky C compilers and linkers they might have.

     No such build tool exists.  Even make itself has wildly different
     dialects.  So we have to build our own.

 What is Module::Build and how does it relate to MakeMaker?
     Module::Build is a project by Ken Williams to supplant MakeMaker.
     Its primary advantages are:

     •       pure perl.  no make, no shell commands

     •       easier to customize

     •       cleaner internals

     •       less cruft

     Module::Build was long the official heir apparent to MakeMaker.  The
     rate of both its development and adoption has slowed in recent years,
     though, and it is unclear what the future holds for it.  That said,
     Module::Build set the stage for _s_o_m_e_t_h_i_n_g to become the heir to
     MakeMaker.  MakeMaker's maintainers have long said that it is a dead
     end and should be kept functioning, while being cautious about
     extending with new features.

MMoodduullee WWrriittiinngg How do I keep my $VERSION up to date without resetting it manually? Often you want to manually set the $VERSION in the main module distribution because this is the version that everybody sees on CPAN and maybe you want to customize it a bit. But for all the other modules in your dist, $VERSION is really just bookkeeping and all that’s important is it goes up every time the module is changed. Doing this by hand is a pain and you often forget.

     Probably the easiest way to do this is using _p_e_r_l_-_r_e_v_e_r_s_i_o_n in
     Perl::Version:

       perl-reversion -bump

     If your version control system supports revision numbers (git doesn't
     easily), the simplest way to do it automatically is to use its
     revision number (you are using version control, right?).

     In CVS, RCS and SVN you use $Revision$ (see the documentation of your
     version control system for details).  Every time the file is checked
     in the $Revision$ will be updated, updating your $VERSION.

     SVN uses a simple integer for $Revision$ so you can adapt it for your
     $VERSION like so:

         ($VERSION) = q$Revision$ =~ /(\d+)/;

     In CVS and RCS version 1.9 is followed by 1.10.  Since CPAN compares
     version numbers numerically we use a sspprriinnttff(()) to convert 1.9 to
     1.009 and 1.10 to 1.010 which compare properly.

         $VERSION = sprintf "%d.%03d", q$Revision$ =~ /(\d+)\.(\d+)/g;

     If branches are involved (ie. $Revision: 1.5.3.4$) it's a little more
     complicated.

         # must be all on one line or MakeMaker will get confused.
         $VERSION = do { my @r = (q$Revision$ =~ /\d+/g); sprintf "%d."."%03d" x $#r, @r };

     In SVN, $Revision$ should be the same for every file in the project
     so they would all have the same $VERSION.  CVS and RCS have a
     different $Revision$ per file so each file will have a different
     $VERSION.  Distributed version control systems, such as SVK, may have
     a different $Revision$ based on who checks out the file, leading to a
     different $VERSION on each machine!  Finally, some distributed
     version control systems, such as darcs, have no concept of revision
     number at all.

 What's this _M_E_T_A_._y_m_l thing and how did it get in my _M_A_N_I_F_E_S_T?!
     _M_E_T_A_._y_m_l is a module meta-data file pioneered by Module::Build and
     automatically generated as part of the 'distdir' target (and thus
     'dist').  See "Module Meta-Data" in ExtUtils::MakeMaker.

     To shut off its generation, pass the "NO_META" flag to
     "WriteMakefile()".

 How do I delete everything not in my _M_A_N_I_F_E_S_T?
     Some folks are surprised that "make distclean" does not delete
     everything not listed in their MANIFEST (thus making a clean
     distribution) but only tells them what they need to delete.  This is
     done because it is considered too dangerous.  While developing your
     module you might write a new file, not add it to the MANIFEST, then
     run a "distclean" and be sad because your new work was deleted.

     If you really want to do this, you can use
     "ExtUtils::Manifest::manifind()" to read the MANIFEST and File::Find
     to delete the files.  But you have to be careful.  Here's a script to
     do that.  Use at your own risk.  Have fun blowing holes in your foot.

         #!/usr/bin/perl -w

         use strict;

         use File::Spec;
         use File::Find;
         use ExtUtils::Manifest qw(maniread);

         my %manifest = map  {( $_ => 1 )}
                        grep { File::Spec->canonpath($_) }
                             keys %{ maniread() };

         if( !keys %manifest ) {
             print "No files found in MANIFEST.  Stopping.\n";
             exit;
         }

         find({
               wanted   => sub {
                   my $path = File::Spec->canonpath($_);

                   return unless -f $path;
                   return if exists $manifest{ $path };

                   print "unlink $path\n";
                   unlink $path;
               },
               no_chdir => 1
              },
              "."
         );

 Which tar should I use on Windows?
     We recommend ptar from Archive::Tar not older than 1.66 with '-C'
     option.

 Which zip should I use on Windows for '[ndg]make zipdist'?
     We recommend InfoZIP: <http://www.info-zip.org/Zip.html>

XXSS #

 How do I prevent "object version X.XX does not match bootstrap parameter
 Y.YY" errors?
     XS code is very sensitive to the module version number and will
     complain if the version number in your Perl module doesn't match.  If
     you change your module's version # without rerunning Makefile.PL the
     old version number will remain in the Makefile, causing the XS code
     to be built with the wrong number.

     To avoid this, you can force the Makefile to be rebuilt whenever you
     change the module containing the version number by adding this to
     your WWrriitteeMMaakkeeffiillee(()) arguments.

         depend => { '$(FIRST_MAKEFILE)' => '$(VERSION_FROM)' }

 How do I make two or more XS files coexist in the same directory?
     Sometimes you need to have two and more XS files in the same package.
     There are three ways: "XSMULTI", separate directories, and
     bootstrapping one XS from another.

     XSMULTI Structure your modules so they are all located under _l_i_b,
             such that "Foo::Bar" is in _l_i_b_/_F_o_o_/_B_a_r_._p_m and _l_i_b_/_F_o_o_/_B_a_r_._x_s,
             etc. Have your top-level "WriteMakefile" set the variable
             "XSMULTI" to a true value.

             Er, that's it.

     Separate directories
             Put each XS files into separate directories, each with their
             own _M_a_k_e_f_i_l_e_._P_L. Make sure each of those _M_a_k_e_f_i_l_e_._P_Ls has the
             correct "CFLAGS", "INC", "LIBS" etc. You will need to make
             sure the top-level _M_a_k_e_f_i_l_e_._P_L refers to each of these using

“DIR”. #

     Bootstrapping
             Let's assume that we have a package "Cool::Foo", which
             includes "Cool::Foo" and "Cool::Bar" modules each having a
             separate XS file. First we use the following _M_a_k_e_f_i_l_e_._P_L:

               use ExtUtils::MakeMaker;

               WriteMakefile(
                   NAME              => 'Cool::Foo',
                   VERSION_FROM      => 'Foo.pm',
                   OBJECT              => q/$(O_FILES)/,
                   # ... other attrs ...
               );

             Notice the "OBJECT" attribute. MakeMaker generates the
             following variables in _M_a_k_e_f_i_l_e:

               # Handy lists of source code files:
               XS_FILES= Bar.xs \
                     Foo.xs
               C_FILES = Bar.c \
                     Foo.c
               O_FILES = Bar.o \
                     Foo.o

             Therefore we can use the "O_FILES" variable to tell MakeMaker
             to use these objects into the shared library.

             That's pretty much it. Now write _F_o_o_._p_m and _F_o_o_._x_s, _B_a_r_._p_m
             and _B_a_r_._x_s, where _F_o_o_._p_m bootstraps the shared library and
             _B_a_r_._p_m simply loading _F_o_o_._p_m.

             The only issue left is to how to bootstrap _B_a_r_._x_s. This is
             done from _F_o_o_._x_s:

               MODULE = Cool::Foo PACKAGE = Cool::Foo

BOOT: #

               # boot the second XS file
               boot_Cool__Bar(aTHX_ cv);

             If you have more than two files, this is the place where you
             should boot extra XS files from.

             The following four files sum up all the details discussed so
             far.

               Foo.pm:
               -------
               package Cool::Foo;

               require DynaLoader;

               our @ISA = qw(DynaLoader);
               our $VERSION = '0.01';
               bootstrap Cool::Foo $VERSION;

               1;

               Bar.pm:
               -------
               package Cool::Bar;

               use Cool::Foo; # bootstraps Bar.xs

               1;

               Foo.xs:
               -------
               #include "EXTERN.h"
               #include "perl.h"
               #include "XSUB.h"

               MODULE = Cool::Foo  PACKAGE = Cool::Foo

BOOT: #

               # boot the second XS file
               boot_Cool__Bar(aTHX_ cv);

               MODULE = Cool::Foo  PACKAGE = Cool::Foo  PREFIX = cool_foo_

               void
               cool_foo_perl_rules()

CODE: #

                   fprintf(stderr, "Cool::Foo says: Perl Rules\n");

               Bar.xs:
               -------
               #include "EXTERN.h"
               #include "perl.h"
               #include "XSUB.h"

               MODULE = Cool::Bar  PACKAGE = Cool::Bar PREFIX = cool_bar_

               void
               cool_bar_perl_rules()

CODE: #

                   fprintf(stderr, "Cool::Bar says: Perl Rules\n");

             And of course a very basic test:

               t/cool.t:
               --------
               use Test;
               BEGIN { plan tests => 1 };
               use Cool::Foo;
               use Cool::Bar;
               Cool::Foo::perl_rules();
               Cool::Bar::perl_rules();
               ok 1;

             This tip has been brought to you by Nick Ing-Simmons and Stas
             Bekman.

             An alternative way to achieve this can be seen in
             Gtk2::CodeGen and Glib::CodeGen.

DDEESSIIGGNN #

MMaakkeeMMaakkeerr oobbjjeecctt hhiieerraarrcchhyy ((ssiimmpplliiffiieedd)) What most people need to know (superclasses on top.)

         ExtUtils::MM_Any
                 |
         ExtUtils::MM_Unix
                 |
         ExtUtils::MM_{Current OS}
                 |
         ExtUtils::MakeMaker
                 |

MY #

 The object actually used is of the class MY which allows you to override
 bits of MakeMaker inside your Makefile.PL by declaring MMYY::::ffoooo(()) methods.

MMaakkeeMMaakkeerr oobbjjeecctt hhiieerraarrcchhyy ((rreeaall)) Here’s how it really works:

                                     ExtUtils::MM_Any
                                             |
                                     ExtUtils::MM_Unix
                                             |
     ExtUtils::Liblist::Kid          ExtUtils::MM_{Current OS} (if necessary)
           |                                          |
     ExtUtils::Liblist     ExtUtils::MakeMaker        |
                     |     |                          |
                     |     |   |-----------------------
                    ExtUtils::MM
                    |          |
         ExtUtils::MY         MM (created by ExtUtils::MM)
         |                                   |
         MY (created by ExtUtils::MY)        |
                     .                       |
                  (mixin)                    |
                     .                       |
                PACK### (created each call to ExtUtils::MakeMaker->new)

 NOTE: Yes, this is a mess.  See
 <http://archive.develooper.com/makemaker@perl.org/msg00134.html> for some
 history.

 NOTE: When ExtUtils::MM is loaded it chooses a superclass for MM from
 amongst the ExtUtils::MM_* modules based on the current operating system.

 NOTE: ExtUtils::MM_{Current OS} represents one of the ExtUtils::MM_*
 modules except ExtUtils::MM_Any chosen based on your operating system.

 NOTE: The main object used by MakeMaker is a PACK### object, *not*
 ExtUtils::MakeMaker.  It is, effectively, a subclass of MY,
 ExtUtils::MakeMaker, ExtUtils::Liblist and ExtUtils::MM_{Current OS}

 NOTE: The methods in MY are simply copied into PACK### rather than MY
 being a superclass of PACK###.  I don't remember the rationale.

 NOTE: ExtUtils::Liblist should be removed from the inheritance hiearchy
 and simply be called as functions.

 NOTE: Modules like File::Spec and Exporter have been omitted for clarity.

TThhee MMMM__ hhiieerraarrcchhyy MM_Win95 MM_NW5 \ / MM_BeOS MM_Cygwin MM_OS2 MM_VMS MM_Win32 MM_DOS MM_UWIN \ | | | / / / ———————————————— | | MM_Unix | | | MM_Any

 NOTE: Each direct MM_Unix subclass is also an MM_Any subclass.  This is a
 temporary hack because MM_Unix overrides some MM_Any methods with Unix
 specific code.  It allows the non-Unix modules to see the original MM_Any
 implementations.

 NOTE: Modules like File::Spec and Exporter have been omitted for clarity.

PPAATTCCHHIINNGG #

 If you have a question you'd like to see added to the FAQ (whether or not
 you have the answer) please either:

 • make a pull request on the MakeMaker github repository

 • raise a issue on the MakeMaker github repository

 • file an RT ticket

 • email makemaker@perl.org

AAUUTTHHOORR #

 The denizens of makemaker@perl.org.

SSEEEE AALLSSOO #

 ExtUtils::MakeMaker

perl v5.36.3 2023-02-15 ExtUtils::MakeMaker::FAQ(3p)