1 package ExtUtils::MakeMaker::FAQ;
3 our $VERSION = '6.79_01';
10 ExtUtils::MakeMaker::FAQ - Frequently Asked Questions About MakeMaker
14 FAQs, tricks and tips for C<ExtUtils::MakeMaker>.
17 =head2 Module Installation
21 =item How do I install a module into my home directory?
23 If you're not the Perl administrator you probably don't have
24 permission to install a module to its default location. Then you
25 should install it for your own use into your home directory like so:
27 # Non-unix folks, replace ~ with /path/to/your/home/dir
28 perl Makefile.PL INSTALL_BASE=~
30 This will put modules into F<~/lib/perl5>, man pages into F<~/man> and
31 programs into F<~/bin>.
33 To ensure your Perl programs can see these newly installed modules,
34 set your C<PERL5LIB> environment variable to F<~/lib/perl5> or tell
35 each of your programs to look in that directory with the following:
37 use lib "$ENV{HOME}/lib/perl5";
39 or if $ENV{HOME} isn't set and you don't want to set it for some
40 reason, do it the long way.
42 use lib "/path/to/your/home/dir/lib/perl5";
45 =item How do I get MakeMaker and Module::Build to install to the same place?
47 Module::Build, as of 0.28, supports two ways to install to the same
48 location as MakeMaker.
50 We highly recommend the install_base method, its the simplest and most
51 closely approximates the expected behavior of an installation prefix.
53 1) Use INSTALL_BASE / C<--install_base>
55 MakeMaker (as of 6.31) and Module::Build (as of 0.28) both can install
56 to the same locations using the "install_base" concept. See
57 L<ExtUtils::MakeMaker/INSTALL_BASE> for details. To get MM and MB to
58 install to the same location simply set INSTALL_BASE in MM and
59 C<--install_base> in MB to the same location.
61 perl Makefile.PL INSTALL_BASE=/whatever
62 perl Build.PL --install_base /whatever
64 This works most like other language's behavior when you specify a
65 prefix. We recommend this method.
67 2) Use PREFIX / C<--prefix>
69 Module::Build 0.28 added support for C<--prefix> which works like
72 perl Makefile.PL PREFIX=/whatever
73 perl Build.PL --prefix /whatever
75 We highly discourage this method. It should only be used if you know
76 what you're doing and specifically need the PREFIX behavior. The
77 PREFIX algorithm is complicated and focused on matching the system
80 =item How do I keep from installing man pages?
82 Recent versions of MakeMaker will only install man pages on Unix-like
85 For an individual module:
87 perl Makefile.PL INSTALLMAN1DIR=none INSTALLMAN3DIR=none
89 If you want to suppress man page installation for all modules you have
90 to reconfigure Perl and tell it 'none' when it asks where to install
94 =item How do I use a module without installing it?
96 Two ways. One is to build the module normally...
102 ...and then set the PERL5LIB environment variable to point at the
103 blib/lib and blib/arch directories.
105 The other is to install the module in a temporary location.
107 perl Makefile.PL INSTALL_BASE=~/tmp
112 And then set PERL5LIB to F<~/tmp/lib/perl5>. This works well when you
113 have multiple modules to work with. It also ensures that the module
114 goes through its full installation process which may modify it.
116 =item PREFIX vs INSTALL_BASE from Module::Build::Cookbook
118 The behavior of PREFIX is complicated and depends closely on how your
119 Perl is configured. The resulting installation locations will vary from
120 machine to machine and even different installations of Perl on the same machine.
121 Because of this, its difficult to document where prefix will place your modules.
123 In contrast, INSTALL_BASE has predictable, easy to explain installation locations.
124 Now that Module::Build and MakeMaker both have INSTALL_BASE there is little reason
125 to use PREFIX other than to preserve your existing installation locations. If you
126 are starting a fresh Perl installation we encourage you to use INSTALL_BASE. If
127 you have an existing installation installed via PREFIX, consider moving it to an
128 installation structure matching INSTALL_BASE and using that instead.
132 =head2 Common errors and problems
136 =item "No rule to make target `/usr/lib/perl5/CORE/config.h', needed by `Makefile'"
138 Just what it says, you're missing that file. MakeMaker uses it to
139 determine if perl has been rebuilt since the Makefile was made. It's
140 a bit of a bug that it halts installation.
142 Some operating systems don't ship the CORE directory with their base
143 perl install. To solve the problem, you likely need to install a perl
144 development package such as perl-devel (CentOS, Fedora and other
145 Redhat systems) or perl (Ubuntu and other Debian systems).
149 =head2 Philosophy and History
153 =item Why not just use <insert other build config tool here>?
155 Why did MakeMaker reinvent the build configuration wheel? Why not
156 just use autoconf or automake or ppm or Ant or ...
158 There are many reasons, but the major one is cross-platform
161 Perl is one of the most ported pieces of software ever. It works on
162 operating systems I've never even heard of (see perlport for details).
163 It needs a build tool that can work on all those platforms and with
164 any wacky C compilers and linkers they might have.
166 No such build tool exists. Even make itself has wildly different
167 dialects. So we have to build our own.
170 =item What is Module::Build and how does it relate to MakeMaker?
172 Module::Build is a project by Ken Williams to supplant MakeMaker.
173 Its primary advantages are:
177 =item * pure perl. no make, no shell commands
179 =item * easier to customize
181 =item * cleaner internals
187 Module::Build is the official heir apparent to MakeMaker and we
188 encourage people to work on M::B rather than spending time adding features
194 =head2 Module Writing
198 =item How do I keep my $VERSION up to date without resetting it manually?
200 Often you want to manually set the $VERSION in the main module
201 distribution because this is the version that everybody sees on CPAN
202 and maybe you want to customize it a bit. But for all the other
203 modules in your dist, $VERSION is really just bookkeeping and all that's
204 important is it goes up every time the module is changed. Doing this
205 by hand is a pain and you often forget.
207 Simplest way to do it automatically is to use your version control
208 system's revision number (you are using version control, right?).
210 In CVS, RCS and SVN you use $Revision$ (see the documentation of your
211 version control system for details). Every time the file is checked
212 in the $Revision$ will be updated, updating your $VERSION.
214 SVN uses a simple integer for $Revision$ so you can adapt it for your
217 ($VERSION) = q$Revision$ =~ /(\d+)/;
219 In CVS and RCS version 1.9 is followed by 1.10. Since CPAN compares
220 version numbers numerically we use a sprintf() to convert 1.9 to 1.009
221 and 1.10 to 1.010 which compare properly.
223 $VERSION = sprintf "%d.%03d", q$Revision$ =~ /(\d+)\.(\d+)/g;
225 If branches are involved (ie. $Revision: 1.5.3.4$) it's a little more
228 # must be all on one line or MakeMaker will get confused.
229 $VERSION = do { my @r = (q$Revision$ =~ /\d+/g); sprintf "%d."."%03d" x $#r, @r };
231 In SVN, $Revision$ should be the same for every file in the project so
232 they would all have the same $VERSION. CVS and RCS have a different
233 $Revision$ per file so each file will have a different $VERSION.
234 Distributed version control systems, such as SVK, may have a different
235 $Revision$ based on who checks out the file, leading to a different $VERSION
236 on each machine! Finally, some distributed version control systems, such
237 as darcs, have no concept of revision number at all.
240 =item What's this F<META.yml> thing and how did it get in my F<MANIFEST>?!
242 F<META.yml> is a module meta-data file pioneered by Module::Build and
243 automatically generated as part of the 'distdir' target (and thus
244 'dist'). See L<ExtUtils::MakeMaker/"Module Meta-Data">.
246 To shut off its generation, pass the C<NO_META> flag to C<WriteMakefile()>.
249 =item How do I delete everything not in my F<MANIFEST>?
251 Some folks are surprised that C<make distclean> does not delete
252 everything not listed in their MANIFEST (thus making a clean
253 distribution) but only tells them what they need to delete. This is
254 done because it is considered too dangerous. While developing your
255 module you might write a new file, not add it to the MANIFEST, then
256 run a C<distclean> and be sad because your new work was deleted.
258 If you really want to do this, you can use
259 C<ExtUtils::Manifest::manifind()> to read the MANIFEST and File::Find
260 to delete the files. But you have to be careful. Here's a script to
261 do that. Use at your own risk. Have fun blowing holes in your foot.
269 use ExtUtils::Manifest qw(maniread);
271 my %manifest = map {( $_ => 1 )}
272 grep { File::Spec->canonpath($_) }
273 keys %{ maniread() };
275 if( !keys %manifest ) {
276 print "No files found in MANIFEST. Stopping.\n";
282 my $path = File::Spec->canonpath($_);
284 return unless -f $path;
285 return if exists $manifest{ $path };
287 print "unlink $path\n";
296 =item Which tar should I use on Windows?
298 We recommend ptar from Archive::Tar not older than 1.66 with '-C' option.
300 =item Which zip should I use on Windows for '[nd]make zipdist'?
302 We recommend InfoZIP: L<http://www.info-zip.org/Zip.html>
311 =item How do I prevent "object version X.XX does not match bootstrap parameter Y.YY" errors?
313 XS code is very sensitive to the module version number and will
314 complain if the version number in your Perl module doesn't match. If
315 you change your module's version # without rerunning Makefile.PL the old
316 version number will remain in the Makefile, causing the XS code to be built
317 with the wrong number.
319 To avoid this, you can force the Makefile to be rebuilt whenever you
320 change the module containing the version number by adding this to your
321 WriteMakefile() arguments.
323 depend => { '$(FIRST_MAKEFILE)' => '$(VERSION_FROM)' }
326 =item How do I make two or more XS files coexist in the same directory?
328 Sometimes you need to have two and more XS files in the same package.
329 One way to go is to put them into separate directories, but sometimes
330 this is not the most suitable solution. The following technique allows
331 you to put two (and more) XS files in the same directory.
333 Let's assume that we have a package C<Cool::Foo>, which includes
334 C<Cool::Foo> and C<Cool::Bar> modules each having a separate XS
335 file. First we use the following I<Makefile.PL>:
337 use ExtUtils::MakeMaker;
341 VERSION_FROM => 'Foo.pm',
342 OBJECT => q/$(O_FILES)/,
343 # ... other attrs ...
346 Notice the C<OBJECT> attribute. MakeMaker generates the following
347 variables in I<Makefile>:
349 # Handy lists of source code files:
357 Therefore we can use the C<O_FILES> variable to tell MakeMaker to use
358 these objects into the shared library.
360 That's pretty much it. Now write I<Foo.pm> and I<Foo.xs>, I<Bar.pm>
361 and I<Bar.xs>, where I<Foo.pm> bootstraps the shared library and
362 I<Bar.pm> simply loading I<Foo.pm>.
364 The only issue left is to how to bootstrap I<Bar.xs>. This is done
367 MODULE = Cool::Foo PACKAGE = Cool::Foo
370 # boot the second XS file
371 boot_Cool__Bar(aTHX_ cv);
373 If you have more than two files, this is the place where you should
374 boot extra XS files from.
376 The following four files sum up all the details discussed so far.
384 our @ISA = qw(DynaLoader);
385 our $VERSION = '0.01';
386 bootstrap Cool::Foo $VERSION;
394 use Cool::Foo; # bootstraps Bar.xs
404 MODULE = Cool::Foo PACKAGE = Cool::Foo
407 # boot the second XS file
408 boot_Cool__Bar(aTHX_ cv);
410 MODULE = Cool::Foo PACKAGE = Cool::Foo PREFIX = cool_foo_
413 cool_foo_perl_rules()
416 fprintf(stderr, "Cool::Foo says: Perl Rules\n");
424 MODULE = Cool::Bar PACKAGE = Cool::Bar PREFIX = cool_bar_
427 cool_bar_perl_rules()
430 fprintf(stderr, "Cool::Bar says: Perl Rules\n");
432 And of course a very basic test:
437 BEGIN { plan tests => 1 };
440 Cool::Foo::perl_rules();
441 Cool::Bar::perl_rules();
444 This tip has been brought to you by Nick Ing-Simmons and Stas Bekman.
450 If you have a question you'd like to see added to the FAQ (whether or
451 not you have the answer) please send it to makemaker@perl.org.
455 The denizens of makemaker@perl.org.
459 L<ExtUtils::MakeMaker>