1ExtUtils::MakeMaker::FAUQs(e3r)Contributed Perl DocumentEaxttiUotnils::MakeMaker::FAQ(3)
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NAME

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

9       FAQs, tricks and tips for "ExtUtils::MakeMaker".
10
11   Module Installation
12       How do I install a module into my home directory?
13           If you're not the Perl administrator you probably don't have
14           permission to install a module to its default location. Ways of
15           handling this with a lot less manual effort on your part are
16           perlbrew and local::lib.
17
18           Otherwise, you can install it for your own use into your home
19           directory like so:
20
21               # Non-unix folks, replace ~ with /path/to/your/home/dir
22               perl Makefile.PL INSTALL_BASE=~
23
24           This will put modules into ~/lib/perl5, man pages into ~/man and
25           programs into ~/bin.
26
27           To ensure your Perl programs can see these newly installed modules,
28           set your "PERL5LIB" environment variable to ~/lib/perl5 or tell
29           each of your programs to look in that directory with the following:
30
31               use lib "$ENV{HOME}/lib/perl5";
32
33           or if $ENV{HOME} isn't set and you don't want to set it for some
34           reason, do it the long way.
35
36               use lib "/path/to/your/home/dir/lib/perl5";
37
38       How do I get MakeMaker and Module::Build to install to the same place?
39           Module::Build, as of 0.28, supports two ways to install to the same
40           location as MakeMaker.
41
42           We highly recommend the install_base method, its the simplest and
43           most closely approximates the expected behavior of an installation
44           prefix.
45
46           1) Use INSTALL_BASE / "--install_base"
47
48           MakeMaker (as of 6.31) and Module::Build (as of 0.28) both can
49           install to the same locations using the "install_base" concept.
50           See "INSTALL_BASE" in ExtUtils::MakeMaker for details.  To get MM
51           and MB to install to the same location simply set INSTALL_BASE in
52           MM and "--install_base" in MB to the same location.
53
54               perl Makefile.PL INSTALL_BASE=/whatever
55               perl Build.PL    --install_base /whatever
56
57           This works most like other language's behavior when you specify a
58           prefix.  We recommend this method.
59
60           2) Use PREFIX / "--prefix"
61
62           Module::Build 0.28 added support for "--prefix" which works like
63           MakeMaker's PREFIX.
64
65               perl Makefile.PL PREFIX=/whatever
66               perl Build.PL    --prefix /whatever
67
68           We highly discourage this method.  It should only be used if you
69           know what you're doing and specifically need the PREFIX behavior.
70           The PREFIX algorithm is complicated and focused on matching the
71           system installation.
72
73       How do I keep from installing man pages?
74           Recent versions of MakeMaker will only install man pages on Unix-
75           like operating systems.
76
77           For an individual module:
78
79                   perl Makefile.PL INSTALLMAN1DIR=none INSTALLMAN3DIR=none
80
81           If you want to suppress man page installation for all modules you
82           have to reconfigure Perl and tell it 'none' when it asks where to
83           install man pages.
84
85       How do I use a module without installing it?
86           Two ways.  One is to build the module normally...
87
88                   perl Makefile.PL
89                   make
90                   make test
91
92           ...and then use blib to point Perl at the built but uninstalled
93           module:
94
95                   perl -Mblib script.pl
96                   perl -Mblib -e '...'
97
98           The other is to install the module in a temporary location.
99
100                   perl Makefile.PL INSTALL_BASE=~/tmp
101                   make
102                   make test
103                   make install
104
105           And then set PERL5LIB to ~/tmp/lib/perl5.  This works well when you
106           have multiple modules to work with.  It also ensures that the
107           module goes through its full installation process which may modify
108           it.  Again, local::lib may assist you here.
109
110       How can I organize tests into subdirectories and have them run?
111           Let's take the following test directory structure:
112
113               t/foo/sometest.t
114               t/bar/othertest.t
115               t/bar/baz/anothertest.t
116
117           Now, inside of the "WriteMakeFile()" function in your Makefile.PL,
118           specify where your tests are located with the "test" directive:
119
120               test => {TESTS => 't/*.t t/*/*.t t/*/*/*.t'}
121
122           The first entry in the string will run all tests in the top-level
123           t/ directory. The second will run all test files located in any
124           subdirectory under t/. The third, runs all test files within any
125           subdirectory within any other subdirectory located under t/.
126
127           Note that you do not have to use wildcards. You can specify
128           explicitly which subdirectories to run tests in:
129
130               test => {TESTS => 't/*.t t/foo/*.t t/bar/baz/*.t'}
131
132       PREFIX vs INSTALL_BASE from Module::Build::Cookbook
133           The behavior of PREFIX is complicated and depends closely on how
134           your Perl is configured. The resulting installation locations will
135           vary from machine to machine and even different installations of
136           Perl on the same machine.  Because of this, its difficult to
137           document where prefix will place your modules.
138
139           In contrast, INSTALL_BASE has predictable, easy to explain
140           installation locations.  Now that Module::Build and MakeMaker both
141           have INSTALL_BASE there is little reason to use PREFIX other than
142           to preserve your existing installation locations. If you are
143           starting a fresh Perl installation we encourage you to use
144           INSTALL_BASE. If you have an existing installation installed via
145           PREFIX, consider moving it to an installation structure matching
146           INSTALL_BASE and using that instead.
147
148       Generating *.pm files with substitutions eg of $VERSION
149           If you want to configure your module files for local conditions, or
150           to automatically insert a version number, you can use EUMM's
151           "PL_FILES" capability, where it will automatically run each *.PL it
152           finds to generate its basename. For instance:
153
154               # Makefile.PL:
155               require 'common.pl';
156               my $version = get_version();
157               my @pms = qw(Foo.pm);
158               WriteMakefile(
159                 NAME => 'Foo',
160                 VERSION => $version,
161                 PM => { map { ($_ => "\$(INST_LIB)/$_") } @pms },
162                 clean => { FILES => join ' ', @pms },
163               );
164
165               # common.pl:
166               sub get_version { '0.04' }
167               sub process { my $v = get_version(); s/__VERSION__/$v/g; }
168               1;
169
170               # Foo.pm.PL:
171               require 'common.pl';
172               $_ = join '', <DATA>;
173               process();
174               my $file = shift;
175               open my $fh, '>', $file or die "$file: $!";
176               print $fh $_;
177               __DATA__
178               package Foo;
179               our $VERSION = '__VERSION__';
180               1;
181
182           You may notice that "PL_FILES" is not specified above, since the
183           default of mapping each .PL file to its basename works well.
184
185           If the generated module were architecture-specific, you could
186           replace "$(INST_LIB)" above with "$(INST_ARCHLIB)", although if you
187           locate modules under lib, that would involve ensuring any "lib/" in
188           front of the module location were removed.
189
190   Common errors and problems
191       "No rule to make target `/usr/lib/perl5/CORE/config.h', needed by
192       `Makefile'"
193           Just what it says, you're missing that file.  MakeMaker uses it to
194           determine if perl has been rebuilt since the Makefile was made.
195           It's a bit of a bug that it halts installation.
196
197           Some operating systems don't ship the CORE directory with their
198           base perl install.  To solve the problem, you likely need to
199           install a perl development package such as perl-devel (CentOS,
200           Fedora and other Redhat systems) or perl (Ubuntu and other Debian
201           systems).
202
203   Philosophy and History
204       Why not just use <insert other build config tool here>?
205           Why did MakeMaker reinvent the build configuration wheel?  Why not
206           just use autoconf or automake or ppm or Ant or ...
207
208           There are many reasons, but the major one is cross-platform
209           compatibility.
210
211           Perl is one of the most ported pieces of software ever.  It works
212           on operating systems I've never even heard of (see perlport for
213           details).  It needs a build tool that can work on all those
214           platforms and with any wacky C compilers and linkers they might
215           have.
216
217           No such build tool exists.  Even make itself has wildly different
218           dialects.  So we have to build our own.
219
220       What is Module::Build and how does it relate to MakeMaker?
221           Module::Build is a project by Ken Williams to supplant MakeMaker.
222           Its primary advantages are:
223
224           ·       pure perl.  no make, no shell commands
225
226           ·       easier to customize
227
228           ·       cleaner internals
229
230           ·       less cruft
231
232           Module::Build was long the official heir apparent to MakeMaker.
233           The rate of both its development and adoption has slowed in recent
234           years, though, and it is unclear what the future holds for it.
235           That said, Module::Build set the stage for something to become the
236           heir to MakeMaker.  MakeMaker's maintainers have long said that it
237           is a dead end and should be kept functioning, while being cautious
238           about extending with new features.
239
240   Module Writing
241       How do I keep my $VERSION up to date without resetting it manually?
242           Often you want to manually set the $VERSION in the main module
243           distribution because this is the version that everybody sees on
244           CPAN and maybe you want to customize it a bit.  But for all the
245           other modules in your dist, $VERSION is really just bookkeeping and
246           all that's important is it goes up every time the module is
247           changed.  Doing this by hand is a pain and you often forget.
248
249           Probably the easiest way to do this is using perl-reversion in
250           Perl::Version:
251
252             perl-reversion -bump
253
254           If your version control system supports revision numbers (git
255           doesn't easily), the simplest way to do it automatically is to use
256           its revision number (you are using version control, right?).
257
258           In CVS, RCS and SVN you use $Revision$ (see the documentation of
259           your version control system for details).  Every time the file is
260           checked in the $Revision$ will be updated, updating your $VERSION.
261
262           SVN uses a simple integer for $Revision$ so you can adapt it for
263           your $VERSION like so:
264
265               ($VERSION) = q$Revision$ =~ /(\d+)/;
266
267           In CVS and RCS version 1.9 is followed by 1.10.  Since CPAN
268           compares version numbers numerically we use a sprintf() to convert
269           1.9 to 1.009 and 1.10 to 1.010 which compare properly.
270
271               $VERSION = sprintf "%d.%03d", q$Revision$ =~ /(\d+)\.(\d+)/g;
272
273           If branches are involved (ie. $Revision: 1.5.3.4$) it's a little
274           more complicated.
275
276               # must be all on one line or MakeMaker will get confused.
277               $VERSION = do { my @r = (q$Revision$ =~ /\d+/g); sprintf "%d."."%03d" x $#r, @r };
278
279           In SVN, $Revision$ should be the same for every file in the project
280           so they would all have the same $VERSION.  CVS and RCS have a
281           different $Revision$ per file so each file will have a different
282           $VERSION.  Distributed version control systems, such as SVK, may
283           have a different $Revision$ based on who checks out the file,
284           leading to a different $VERSION on each machine!  Finally, some
285           distributed version control systems, such as darcs, have no concept
286           of revision number at all.
287
288       What's this META.yml thing and how did it get in my MANIFEST?!
289           META.yml is a module meta-data file pioneered by Module::Build and
290           automatically generated as part of the 'distdir' target (and thus
291           'dist').  See "Module Meta-Data" in ExtUtils::MakeMaker.
292
293           To shut off its generation, pass the "NO_META" flag to
294           "WriteMakefile()".
295
296       How do I delete everything not in my MANIFEST?
297           Some folks are surprised that "make distclean" does not delete
298           everything not listed in their MANIFEST (thus making a clean
299           distribution) but only tells them what they need to delete.  This
300           is done because it is considered too dangerous.  While developing
301           your module you might write a new file, not add it to the MANIFEST,
302           then run a "distclean" and be sad because your new work was
303           deleted.
304
305           If you really want to do this, you can use
306           "ExtUtils::Manifest::manifind()" to read the MANIFEST and
307           File::Find to delete the files.  But you have to be careful.
308           Here's a script to do that.  Use at your own risk.  Have fun
309           blowing holes in your foot.
310
311               #!/usr/bin/perl -w
312
313               use strict;
314
315               use File::Spec;
316               use File::Find;
317               use ExtUtils::Manifest qw(maniread);
318
319               my %manifest = map  {( $_ => 1 )}
320                              grep { File::Spec->canonpath($_) }
321                                   keys %{ maniread() };
322
323               if( !keys %manifest ) {
324                   print "No files found in MANIFEST.  Stopping.\n";
325                   exit;
326               }
327
328               find({
329                     wanted   => sub {
330                         my $path = File::Spec->canonpath($_);
331
332                         return unless -f $path;
333                         return if exists $manifest{ $path };
334
335                         print "unlink $path\n";
336                         unlink $path;
337                     },
338                     no_chdir => 1
339                    },
340                    "."
341               );
342
343       Which tar should I use on Windows?
344           We recommend ptar from Archive::Tar not older than 1.66 with '-C'
345           option.
346
347       Which zip should I use on Windows for '[ndg]make zipdist'?
348           We recommend InfoZIP: <http://www.info-zip.org/Zip.html>
349
350   XS
351       How do I prevent "object version X.XX does not match bootstrap
352       parameter Y.YY" errors?
353           XS code is very sensitive to the module version number and will
354           complain if the version number in your Perl module doesn't match.
355           If you change your module's version # without rerunning Makefile.PL
356           the old version number will remain in the Makefile, causing the XS
357           code to be built with the wrong number.
358
359           To avoid this, you can force the Makefile to be rebuilt whenever
360           you change the module containing the version number by adding this
361           to your WriteMakefile() arguments.
362
363               depend => { '$(FIRST_MAKEFILE)' => '$(VERSION_FROM)' }
364
365       How do I make two or more XS files coexist in the same directory?
366           Sometimes you need to have two and more XS files in the same
367           package.  There are three ways: "XSMULTI", separate directories,
368           and bootstrapping one XS from another.
369
370           XSMULTI Structure your modules so they are all located under lib,
371                   such that "Foo::Bar" is in lib/Foo/Bar.pm and
372                   lib/Foo/Bar.xs, etc. Have your top-level "WriteMakefile"
373                   set the variable "XSMULTI" to a true value.
374
375                   Er, that's it.
376
377           Separate directories
378                   Put each XS files into separate directories, each with
379                   their own Makefile.PL. Make sure each of those Makefile.PLs
380                   has the correct "CFLAGS", "INC", "LIBS" etc. You will need
381                   to make sure the top-level Makefile.PL refers to each of
382                   these using "DIR".
383
384           Bootstrapping
385                   Let's assume that we have a package "Cool::Foo", which
386                   includes "Cool::Foo" and "Cool::Bar" modules each having a
387                   separate XS file. First we use the following Makefile.PL:
388
389                     use ExtUtils::MakeMaker;
390
391                     WriteMakefile(
392                         NAME              => 'Cool::Foo',
393                         VERSION_FROM      => 'Foo.pm',
394                         OBJECT              => q/$(O_FILES)/,
395                         # ... other attrs ...
396                     );
397
398                   Notice the "OBJECT" attribute. MakeMaker generates the
399                   following variables in Makefile:
400
401                     # Handy lists of source code files:
402                     XS_FILES= Bar.xs \
403                           Foo.xs
404                     C_FILES = Bar.c \
405                           Foo.c
406                     O_FILES = Bar.o \
407                           Foo.o
408
409                   Therefore we can use the "O_FILES" variable to tell
410                   MakeMaker to use these objects into the shared library.
411
412                   That's pretty much it. Now write Foo.pm and Foo.xs, Bar.pm
413                   and Bar.xs, where Foo.pm bootstraps the shared library and
414                   Bar.pm simply loading Foo.pm.
415
416                   The only issue left is to how to bootstrap Bar.xs. This is
417                   done from Foo.xs:
418
419                     MODULE = Cool::Foo PACKAGE = Cool::Foo
420
421                     BOOT:
422                     # boot the second XS file
423                     boot_Cool__Bar(aTHX_ cv);
424
425                   If you have more than two files, this is the place where
426                   you should boot extra XS files from.
427
428                   The following four files sum up all the details discussed
429                   so far.
430
431                     Foo.pm:
432                     -------
433                     package Cool::Foo;
434
435                     require DynaLoader;
436
437                     our @ISA = qw(DynaLoader);
438                     our $VERSION = '0.01';
439                     bootstrap Cool::Foo $VERSION;
440
441                     1;
442
443                     Bar.pm:
444                     -------
445                     package Cool::Bar;
446
447                     use Cool::Foo; # bootstraps Bar.xs
448
449                     1;
450
451                     Foo.xs:
452                     -------
453                     #include "EXTERN.h"
454                     #include "perl.h"
455                     #include "XSUB.h"
456
457                     MODULE = Cool::Foo  PACKAGE = Cool::Foo
458
459                     BOOT:
460                     # boot the second XS file
461                     boot_Cool__Bar(aTHX_ cv);
462
463                     MODULE = Cool::Foo  PACKAGE = Cool::Foo  PREFIX = cool_foo_
464
465                     void
466                     cool_foo_perl_rules()
467
468                         CODE:
469                         fprintf(stderr, "Cool::Foo says: Perl Rules\n");
470
471                     Bar.xs:
472                     -------
473                     #include "EXTERN.h"
474                     #include "perl.h"
475                     #include "XSUB.h"
476
477                     MODULE = Cool::Bar  PACKAGE = Cool::Bar PREFIX = cool_bar_
478
479                     void
480                     cool_bar_perl_rules()
481
482                         CODE:
483                         fprintf(stderr, "Cool::Bar says: Perl Rules\n");
484
485                   And of course a very basic test:
486
487                     t/cool.t:
488                     --------
489                     use Test;
490                     BEGIN { plan tests => 1 };
491                     use Cool::Foo;
492                     use Cool::Bar;
493                     Cool::Foo::perl_rules();
494                     Cool::Bar::perl_rules();
495                     ok 1;
496
497                   This tip has been brought to you by Nick Ing-Simmons and
498                   Stas Bekman.
499
500                   An alternative way to achieve this can be seen in
501                   Gtk2::CodeGen and Glib::CodeGen.
502

DESIGN

504   MakeMaker object hierarchy (simplified)
505       What most people need to know (superclasses on top.)
506
507               ExtUtils::MM_Any
508                       |
509               ExtUtils::MM_Unix
510                       |
511               ExtUtils::MM_{Current OS}
512                       |
513               ExtUtils::MakeMaker
514                       |
515                      MY
516
517       The object actually used is of the class MY which allows you to
518       override bits of MakeMaker inside your Makefile.PL by declaring
519       MY::foo() methods.
520
521   MakeMaker object hierarchy (real)
522       Here's how it really works:
523
524                                           ExtUtils::MM_Any
525                                                   |
526                                           ExtUtils::MM_Unix
527                                                   |
528           ExtUtils::Liblist::Kid          ExtUtils::MM_{Current OS} (if necessary)
529                 |                                          |
530           ExtUtils::Liblist     ExtUtils::MakeMaker        |
531                           |     |                          |
532                           |     |   |-----------------------
533                          ExtUtils::MM
534                          |          |
535               ExtUtils::MY         MM (created by ExtUtils::MM)
536               |                                   |
537               MY (created by ExtUtils::MY)        |
538                           .                       |
539                        (mixin)                    |
540                           .                       |
541                      PACK### (created each call to ExtUtils::MakeMaker->new)
542
543       NOTE: Yes, this is a mess.  See
544       <http://archive.develooper.com/makemaker@perl.org/msg00134.html> for
545       some history.
546
547       NOTE: When ExtUtils::MM is loaded it chooses a superclass for MM from
548       amongst the ExtUtils::MM_* modules based on the current operating
549       system.
550
551       NOTE: ExtUtils::MM_{Current OS} represents one of the ExtUtils::MM_*
552       modules except ExtUtils::MM_Any chosen based on your operating system.
553
554       NOTE: The main object used by MakeMaker is a PACK### object, *not*
555       ExtUtils::MakeMaker.  It is, effectively, a subclass of MY,
556       ExtUtils::Makemaker, ExtUtils::Liblist and ExtUtils::MM_{Current OS}
557
558       NOTE: The methods in MY are simply copied into PACK### rather than MY
559       being a superclass of PACK###.  I don't remember the rationale.
560
561       NOTE: ExtUtils::Liblist should be removed from the inheritance hiearchy
562       and simply be called as functions.
563
564       NOTE: Modules like File::Spec and Exporter have been omitted for
565       clarity.
566
567   The MM_* hierarchy
568                                       MM_Win95   MM_NW5
569                                            \      /
570        MM_BeOS  MM_Cygwin  MM_OS2  MM_VMS  MM_Win32  MM_DOS  MM_UWIN
571              \        |      |         |        /      /      /
572               ------------------------------------------------
573                                  |       |
574                               MM_Unix    |
575                                     |    |
576                                     MM_Any
577
578       NOTE: Each direct MM_Unix subclass is also an MM_Any subclass.  This is
579       a temporary hack because MM_Unix overrides some MM_Any methods with
580       Unix specific code.  It allows the non-Unix modules to see the original
581       MM_Any implementations.
582
583       NOTE: Modules like File::Spec and Exporter have been omitted for
584       clarity.
585

PATCHING

587       If you have a question you'd like to see added to the FAQ (whether or
588       not you have the answer) please either:
589
590       · make a pull request on the MakeMaker github repository
591
592       · raise a issue on the MakeMaker github repository
593
594       · file an RT ticket
595
596       · email makemaker@perl.org
597

AUTHOR

599       The denizens of makemaker@perl.org.
600

SEE ALSO

602       ExtUtils::MakeMaker
603
604
605
606perl v5.28.0                      2018-03-19       ExtUtils::MakeMaker::FAQ(3)
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