Module::Build - Build and install Perl modules
Standard process for building & installing modules:
- perl Build.PL
- ./Build
- ./Build test
- ./Build install
Or, if you're on a platform (like DOS or Windows) that doesn't require the "./" notation, you can do this:
- perl Build.PL
- Build
- Build test
- Build install
Module::Build
is a system for building, testing, and installing
Perl modules. It is meant to be an alternative to
ExtUtils::MakeMaker
. Developers may alter the behavior of the
module through subclassing in a much more straightforward way than
with MakeMaker
. It also does not require a make
on your system
- most of the Module::Build
code is pure-perl and written in a very
cross-platform way. In fact, you don't even need a shell, so even
platforms like MacOS (traditional) can use it fairly easily. Its only
prerequisites are modules that are included with perl 5.6.0, and it
works fine on perl 5.005 if you can install a few additional modules.
See MOTIVATIONS for more comparisons between ExtUtils::MakeMaker
and Module::Build
.
To install Module::Build
, and any other module that uses
Module::Build
for its installation process, do the following:
- perl Build.PL # 'Build.PL' script creates the 'Build' script
- ./Build # Need ./ to ensure we're using this "Build" script
- ./Build test # and not another one that happens to be in the PATH
- ./Build install
This illustrates initial configuration and the running of three 'actions'. In this case the actions run are 'build' (the default action), 'test', and 'install'. Other actions defined so far include:
<action_list>
You can run the 'help' action for a complete list of actions.
The documentation for Module::Build
is broken up into three sections:
This is the document you are currently reading. It describes basic
usage and background information. Its main purpose is to assist the
user who wants to learn how to invoke and control Module::Build
scripts at the command line.
This document describes the structure and organization of
Module::Build
, and the relevant concepts needed by authors who are
writing Build.PL scripts for a distribution or controlling
Module::Build
processes programmatically.
This is a reference to the Module::Build
API.
This document demonstrates how to accomplish many common tasks. It covers general command line usage and authoring of Build.PL scripts. Includes working examples.
There are some general principles at work here. First, each task when building a module is called an "action". These actions are listed above; they correspond to the building, testing, installing, packaging, etc., tasks.
Second, arguments are processed in a very systematic way. Arguments
are always key=value pairs. They may be specified at perl Build.PL
time (i.e. perl Build.PL destdir=/my/secret/place), in which case
their values last for the lifetime of the Build
script. They may
also be specified when executing a particular action (i.e.
Build test verbose=1
), in which case their values last only for the
lifetime of that command. Per-action command line parameters take
precedence over parameters specified at perl Build.PL
time.
The build process also relies heavily on the Config.pm
module.
If the user wishes to override any of the
values in Config.pm
, she may specify them like so:
- perl Build.PL --config cc=gcc --config ld=gcc
The following build actions are provided by default.
[version 0.01]
If you run the Build
script without any arguments, it runs the
build
action, which in turn runs the code
and docs
actions.
This is analogous to the MakeMaker
make all target.
[version 0.01]
This action will clean up any files that the build process may have
created, including the blib/
directory (but not including the
_build/
directory and the Build
script itself).
[version 0.20]
This action builds your code base.
By default it just creates a blib/
directory and copies any .pm
and .pod files from your lib/
directory into the blib/
directory. It also compiles any .xs files from lib/
and places
them in blib/
. Of course, you need a working C compiler (probably
the same one that built perl itself) for the compilation to work
properly.
The code
action also runs any .PL files in your lib/
directory. Typically these create other files, named the same but
without the .PL ending. For example, a file lib/Foo/Bar.pm.PL
could create the file lib/Foo/Bar.pm. The .PL files are
processed first, so any .pm files (or other kinds that we deal
with) will get copied correctly.
[version 0.26]
...
[version 0.14]
This action will compare the files about to be installed with their installed counterparts. For .pm and .pod files, a diff will be shown (this currently requires a 'diff' program to be in your PATH). For other files like compiled binary files, we simply report whether they differ.
A flags
parameter may be passed to the action, which will be passed
to the 'diff' program. Consult your 'diff' documentation for the
parameters it will accept - a good one is -u
:
- ./Build diff flags=-u
[version 0.02]
This action is helpful for module authors who want to package up their module for source distribution through a medium like CPAN. It will create a tarball of the files listed in MANIFEST and compress the tarball using GZIP compression.
By default, this action will use the Archive::Tar
module. However, you can
force it to use binary "tar" and "gzip" executables by supplying an explicit
tar
(and optional gzip
) parameter:
- ./Build dist --tar C:\path\to\tar.exe --gzip C:\path\to\zip.exe
[version 0.05]
Reports which files are in the build directory but not in the MANIFEST file, and vice versa. (See manifest for details.)
[version 0.05]
Performs the 'realclean' action and then the 'distcheck' action.
[version 0.05]
Creates a "distribution directory" named $dist_name-$dist_version
(if that directory already exists, it will be removed first), then
copies all the files listed in the MANIFEST file to that directory.
This directory is what the distribution tarball is created from.
[version 0.21]
Creates the META.yml file that describes the distribution.
META.yml is a file containing various bits of metadata about the
distribution. The metadata includes the distribution name, version,
abstract, prerequisites, license, and various other data about the
distribution. This file is created as META.yml in YAML format.
It is recommended that the YAML::Tiny
module be installed to create it.
If the YAML::Tiny
module is not installed, an internal module supplied
with Module::Build will be used to write the META.yml file, and this
will most likely be fine.
META.yml file must also be listed in MANIFEST - if it's not, a warning will be issued.
The current version of the META.yml specification can be found at http://module-build.sourceforge.net/META-spec-current.html
[version 0.16]
Uses Module::Signature
to create a SIGNATURE file for your
distribution, and adds the SIGNATURE file to the distribution's
MANIFEST.
[version 0.05]
Performs the 'distdir' action, then switches into that directory and
runs a perl Build.PL
, followed by the 'build' and 'test' actions in
that directory.
[version 0.20]
This will generate documentation (e.g. Unix man pages and HTML
documents) for any installable items under blib/ that
contain POD. If there are no bindoc
or libdoc
installation
targets defined (as will be the case on systems that don't support
Unix manpages) no action is taken for manpages. If there are no
binhtml
or libhtml
installation targets defined no action is
taken for HTML documents.
[version 0.02]
This is just like the install
action, but it won't actually do
anything, it will just report what it would have done if you had
actually run the install
action.
[version 0.03]
This action will simply print out a message that is meant to help you use the build process. It will show you a list of available build actions too.
With an optional argument specifying an action name (e.g. Build help
test
), the 'help' action will show you any POD documentation it can
find for that action.
[version 0.26]
This will generate HTML documentation for any binary or library files
under blib/ that contain POD. The HTML documentation will only be
installed if the install paths can be determined from values in
Config.pm
. You can also supply or override install paths on the
command line by specifying install_path
values for the binhtml
and/or libhtml
installation targets.
[version 0.01]
This action will use ExtUtils::Install
to install the files from
blib/
into the system. See INSTALL PATHS
for details about how Module::Build determines where to install
things, and how to influence this process.
If you want the installation process to look around in @INC
for
other versions of the stuff you're installing and try to delete it,
you can use the uninst
parameter, which tells ExtUtils::Install
to
do so:
- ./Build install uninst=1
This can be a good idea, as it helps prevent multiple versions of a module from being present on your system, which can be a confusing situation indeed.
[version 0.36]
This action will use the cpan_client
parameter as a command to install
missing prerequisites. You will be prompted whether to install
optional dependencies.
The cpan_client
option defaults to 'cpan' but can be set as an option or in
.modulebuildrc. It must be a shell command that takes a list of modules to
install as arguments (e.g. 'cpanp -i' for CPANPLUS). If the program part is a
relative path (e.g. 'cpan' or 'cpanp'), it will be located relative to the perl
program that executed Build.PL.
- /opt/perl/5.8.9/bin/perl Build.PL
- ./Build installdeps --cpan_client 'cpanp -i'
- # installs to 5.8.9
[version 0.05]
This is an action intended for use by module authors, not people installing modules. It will bring the MANIFEST up to date with the files currently present in the distribution. You may use a MANIFEST.SKIP file to exclude certain files or directories from inclusion in the MANIFEST. MANIFEST.SKIP should contain a bunch of regular expressions, one per line. If a file in the distribution directory matches any of the regular expressions, it won't be included in the MANIFEST.
The following is a reasonable MANIFEST.SKIP starting point, you can add your own stuff to it:
- ^_build
- ^Build$
- ^blib
- ~$
- \.bak$
- ^MANIFEST\.SKIP$
- CVS
See the distcheck and skipcheck actions if you want to find out
what the manifest
action would do, without actually doing anything.
[version 0.28]
This will generate man pages for any binary or library files under
blib/ that contain POD. The man pages will only be installed if the
install paths can be determined from values in Config.pm
. You can
also supply or override install paths by specifying there values on
the command line with the bindoc
and libdoc
installation
targets.
[version 0.2806]
Generates a PAR binary distribution for use with PAR or PAR::Dist.
It requires that the PAR::Dist module (version 0.17 and up) is installed on your system.
[version 0.20]
Build a PPD file for your distribution.
This action takes an optional argument codebase
which is used in
the generated PPD file to specify the (usually relative) URL of the
distribution. By default, this value is the distribution name without
any path information.
Example:
- ./Build ppd --codebase "MSWin32-x86-multi-thread/Module-Build-0.21.tar.gz"
[version 0.23]
Generates a PPM binary distribution and a PPD description file. This
action also invokes the ppd
action, so it can accept the same
codebase
argument described under that action.
This uses the same mechanism as the dist
action to tar & zip its
output, so you can supply tar
and/or gzip
parameters to affect
the result.
[version 0.32]
This action prints out a Perl data structure of all prerequisites and the versions
required. The output can be loaded again using eval(). This can be useful for
external tools that wish to query a Build script for prerequisites.
[version 0.28]
This action prints out a list of all prerequisites, the versions required, and the versions actually installed. This can be useful for reviewing the configuration of your system prior to a build, or when compiling data to send for a bug report.
[version 0.28]
This action is identical to the install
action. In the future,
though, when install
starts writing to the file
$(INSTALLARCHLIB)/perllocal.pod, pure_install
won't, and that
will be the only difference between them.
[version 0.01]
This action is just like the clean
action, but also removes the
_build
directory and the Build
script. If you run the
realclean
action, you are essentially starting over, so you will
have to re-create the Build
script again.
[version 0.2806]
This is just like the test
action, but doesn't actually build the
distribution first, and doesn't add blib/ to the load path, and
therefore will test against a previously installed version of the
distribution. This can be used to verify that a certain installed
distribution still works, or to see whether newer versions of a
distribution still pass the old regression tests, and so on.
[version 0.05]
Reports which files are skipped due to the entries in the MANIFEST.SKIP file (See manifest for details)
[version 0.01]
This will use Test::Harness
or TAP::Harness
to run any regression
tests and report their results. Tests can be defined in the standard
places: a file called test.pl
in the top-level directory, or several
files ending with .t in a t/
directory.
If you want tests to be 'verbose', i.e. show details of test execution
rather than just summary information, pass the argument verbose=1
.
If you want to run tests under the perl debugger, pass the argument
debugger=1
.
If you want to have Module::Build find test files with different file
name extensions, pass the test_file_exts
argument with an array
of extensions, such as [qw( .t .s .z )]
.
If you want test to be run by TAP::Harness
, rather than Test::Harness
,
pass the argument tap_harness_args
as an array reference of arguments to
pass to the TAP::Harness constructor.
In addition, if a file called visual.pl
exists in the top-level
directory, this file will be executed as a Perl script and its output
will be shown to the user. This is a good place to put speed tests or
other tests that don't use the Test::Harness
format for output.
To override the choice of tests to run, you may pass a test_files
argument whose value is a whitespace-separated list of test scripts to
run. This is especially useful in development, when you only want to
run a single test to see whether you've squashed a certain bug yet:
- ./Build test --test_files t/something_failing.t
You may also pass several test_files
arguments separately:
- ./Build test --test_files t/one.t --test_files t/two.t
or use a glob()-style pattern:
- ./Build test --test_files 't/01-*.t'
[version 0.2807]
[Note: the 'testall' action and the code snippets below are currently in alpha stage, see http://www.nntp.perl.org/group/perl.module.build/2007/03/msg584.html ]
Runs the test
action plus each of the test$type
actions defined by
the keys of the test_types
parameter.
Currently, you need to define the ACTION_test$type method yourself and enumerate them in the test_types parameter.
- my $mb = Module::Build->subclass(
- code => q(
- sub ACTION_testspecial { shift->generic_test(type => 'special'); }
- sub ACTION_testauthor { shift->generic_test(type => 'author'); }
- )
- )->new(
- ...
- test_types => {
- special => '.st',
- author => ['.at', '.pt' ],
- },
- ...
[version 0.26]
Runs the test
action using Devel::Cover
, generating a
code-coverage report showing which parts of the code were actually
exercised during the tests.
To pass options to Devel::Cover
, set the $DEVEL_COVER_OPTIONS
environment variable:
- DEVEL_COVER_OPTIONS=-ignore,Build ./Build testcover
[version 0.05]
This is a synonym for the 'test' action with the debugger=1
argument.
[version 0.25]
This checks all the files described in the docs
action and
produces Test::Harness
-style output. If you are a module author,
this is useful to run before creating a new release.
[version 0.28]
This checks the pod coverage of the distribution and
produces Test::Harness
-style output. If you are a module author,
this is useful to run before creating a new release.
[version 0.16]
** Note: since only.pm
is so new, and since we just recently added
support for it here too, this feature is to be considered
experimental. **
If you have the only.pm
module installed on your system, you can
use this action to install a module into the version-specific library
trees. This means that you can have several versions of the same
module installed and use a specific one like this:
- use only MyModule => 0.55;
To override the default installation libraries in only::config
,
specify the versionlib
parameter when you run the Build.PL
script:
- perl Build.PL --versionlib /my/version/place/
To override which version the module is installed as, specify the
versionlib
parameter when you run the Build.PL
script:
- perl Build.PL --version 0.50
See the only.pm
documentation for more information on
version-specific installs.
The following options can be used during any invocation of Build.PL
or the Build script, during any action. For information on other
options specific to an action, see the documentation for the
respective action.
NOTE: There is some preliminary support for options to use the more
familiar long option style. Most options can be preceded with the
--
long option prefix, and the underscores changed to dashes
(e.g. --use-rcfile
). Additionally, the argument to boolean options is
optional, and boolean options can be negated by prefixing them with
no or no- (e.g. --noverbose
or --no-verbose
).
Suppress informative messages on output.
Display extra information about the Build on output.
Sets the cpan_client
command for use with the installdeps
action.
See installdeps
for more details.
Load the ~/.modulebuildrc option file. This option can be set to false to prevent the custom resource file from being loaded.
Suppresses the check upon startup that the version of Module::Build
we're now running under is the same version that was initially invoked
when building the distribution (i.e. when the Build.PL
script was
first run). As of 0.3601, a mismatch results in a warning instead of
a fatal error, so this option effectively just suppresses the warning.
Prints Module::Build debugging information to STDOUT, such as a trace of executed build actions.
[version 0.28]
When Module::Build starts up, it will look first for a file,
$ENV{HOME}/.modulebuildrc. If it's not found there, it will look
in the the .modulebuildrc file in the directories referred to by
the environment variables HOMEDRIVE
+ HOMEDIR
, USERPROFILE
,
APPDATA
, WINDIR
, SYS$LOGIN
. If the file exists, the options
specified there will be used as defaults, as if they were typed on the
command line. The defaults can be overridden by specifying new values
on the command line.
The action name must come at the beginning of the line, followed by any
amount of whitespace and then the options. Options are given the same
as they would be on the command line. They can be separated by any
amount of whitespace, including newlines, as long there is whitespace at
the beginning of each continued line. Anything following a hash mark (#
)
is considered a comment, and is stripped before parsing. If more than
one line begins with the same action name, those lines are merged into
one set of options.
Besides the regular actions, there are two special pseudo-actions: the
key *
(asterisk) denotes any global options that should be applied
to all actions, and the key 'Build_PL' specifies options to be applied
when you invoke perl Build.PL
.
- * verbose=1 # global options
- diff flags=-u
- install --install_base /home/ken
- --install_path html=/home/ken/docs/html
- installdeps --cpan_client 'cpanp -i'
If you wish to locate your resource file in a different location, you
can set the environment variable MODULEBUILDRC
to the complete
absolute path of the file containing your options.
[version 0.28]
Specifies an alternate location for a default options file as described above.
[version 0.36]
Command line options that are applied to Build.PL or any Build action. The string is split as the shell would (e.g. whitespace) and the result is prepended to any actual command-line arguments.
[version 0.19]
When you invoke Module::Build's build
action, it needs to figure
out where to install things. The nutshell version of how this works
is that default installation locations are determined from
Config.pm, and they may be overridden by using the install_path
parameter. An install_base
parameter lets you specify an
alternative installation root like /home/foo, and a destdir
lets
you specify a temporary installation directory like /tmp/install in
case you want to create bundled-up installable packages.
Natively, Module::Build provides default installation locations for the following types of installable items:
Usually pure-Perl module files ending in .pm.
"Architecture-dependent" module files, usually produced by compiling XS, Inline, or similar code.
Programs written in pure Perl. In order to improve reuse, try to make these as small as possible - put the code into modules whenever possible.
"Architecture-dependent" executable programs, i.e. compiled C code or something. Pretty rare to see this in a perl distribution, but it happens.
Documentation for the stuff in script
and bin
. Usually
generated from the POD in those files. Under Unix, these are manual
pages belonging to the 'man1' category.
Documentation for the stuff in lib
and arch
. This is usually
generated from the POD in .pm files. Under Unix, these are manual
pages belonging to the 'man3' category.
This is the same as bindoc
above, but applies to HTML documents.
This is the same as bindoc
above, but applies to HTML documents.
Four other parameters let you control various aspects of how installation paths are determined:
The default destinations for these installable things come from
entries in your system's Config.pm
. You can select from three
different sets of default locations by setting the installdirs
parameter as follows:
- 'installdirs' set to:
- core site vendor
- uses the following defaults from Config.pm:
- lib => installprivlib installsitelib installvendorlib
- arch => installarchlib installsitearch installvendorarch
- script => installscript installsitebin installvendorbin
- bin => installbin installsitebin installvendorbin
- bindoc => installman1dir installsiteman1dir installvendorman1dir
- libdoc => installman3dir installsiteman3dir installvendorman3dir
- binhtml => installhtml1dir installsitehtml1dir installvendorhtml1dir [*]
- libhtml => installhtml3dir installsitehtml3dir installvendorhtml3dir [*]
- * Under some OS (eg. MSWin32) the destination for HTML documents is
- determined by the C<Config.pm> entry C<installhtmldir>.
The default value of installdirs
is "site". If you're creating
vendor distributions of module packages, you may want to do something
like this:
- perl Build.PL --installdirs vendor
or
- ./Build install --installdirs vendor
If you're installing an updated version of a module that was included
with perl itself (i.e. a "core module"), then you may set
installdirs
to "core" to overwrite the module in its present
location.
(Note that the 'script' line is different from MakeMaker
-
unfortunately there's no such thing as "installsitescript" or
"installvendorscript" entry in Config.pm
, so we use the
"installsitebin" and "installvendorbin" entries to at least get the
general location right. In the future, if Config.pm
adds some more
appropriate entries, we'll start using those.)
Once the defaults have been set, you can override them.
On the command line, that would look like this:
- perl Build.PL --install_path lib=/foo/lib --install_path arch=/foo/lib/arch
or this:
- ./Build install --install_path lib=/foo/lib --install_path arch=/foo/lib/arch
You can also set the whole bunch of installation paths by supplying the
install_base
parameter to point to a directory on your system. For
instance, if you set install_base
to "/home/ken" on a Linux
system, you'll install as follows:
- lib => /home/ken/lib/perl5
- arch => /home/ken/lib/perl5/i386-linux
- script => /home/ken/bin
- bin => /home/ken/bin
- bindoc => /home/ken/man/man1
- libdoc => /home/ken/man/man3
- binhtml => /home/ken/html
- libhtml => /home/ken/html
Note that this is different from how MakeMaker
's PREFIX
parameter works. install_base
just gives you a default layout under the
directory you specify, which may have little to do with the
installdirs=site
layout.
The exact layout under the directory you specify may vary by system - we try to do the "sensible" thing on each platform.
If you want to install everything into a temporary directory first
(for instance, if you want to create a directory tree that a package
manager like rpm
or dpkg
could create a package from), you can
use the destdir
parameter:
- perl Build.PL --destdir /tmp/foo
or
- ./Build install --destdir /tmp/foo
This will effectively install to "/tmp/foo/$sitelib",
"/tmp/foo/$sitearch", and the like, except that it will use
File::Spec
to make the pathnames work correctly on whatever
platform you're installing on.
Provided for compatibility with ExtUtils::MakeMaker
's PREFIX argument.
prefix
should be used when you wish Module::Build to install your
modules, documentation and scripts in the same place
ExtUtils::MakeMaker
does.
The following are equivalent.
- perl Build.PL --prefix /tmp/foo
- perl Makefile.PL PREFIX=/tmp/foo
Because of the very complex nature of the prefixification logic, the
behavior of PREFIX in MakeMaker
has changed subtly over time.
Module::Build's --prefix logic is equivalent to the PREFIX logic found
in ExtUtils::MakeMaker
6.30.
If you do not need to retain compatibility with ExtUtils::MakeMaker
or
are starting a fresh Perl installation we recommend you use
install_base
instead (and INSTALL_BASE
in ExtUtils::MakeMaker
).
See Instaling in the same location as ExtUtils::MakeMaker in Module::Build::Cookbook for further information.
There are several reasons I wanted to start over, and not just fix
what I didn't like about MakeMaker
:
I don't like the core idea of MakeMaker
, namely that make
should be
involved in the build process. Here are my reasons:
When a person is installing a Perl module, what can you assume about
their environment? Can you assume they have make
? No, but you can
assume they have some version of Perl.
When a person is writing a Perl module for intended distribution, can you assume that they know how to build a Makefile, so they can customize their build process? No, but you can assume they know Perl, and could customize that way.
For years, these things have been a barrier to people getting the build/install process to do what they want.
There are several architectural decisions in MakeMaker
that make it
very difficult to customize its behavior. For instance, when using
MakeMaker
you do use ExtUtils::MakeMaker
, but the object created in
WriteMakefile()
is actually blessed into a package name that's
created on the fly, so you can't simply subclass
ExtUtils::MakeMaker
. There is a workaround MY
package that lets
you override certain MakeMaker
methods, but only certain explicitly
preselected (by MakeMaker
) methods can be overridden. Also, the method
of customization is very crude: you have to modify a string containing
the Makefile text for the particular target. Since these strings
aren't documented, and can't be documented (they take on different
values depending on the platform, version of perl, version of
MakeMaker
, etc.), you have no guarantee that your modifications will
work on someone else's machine or after an upgrade of MakeMaker
or
perl.
It is risky to make major changes to MakeMaker
, since it does so many
things, is so important, and generally works. Module::Build
is an
entirely separate package so that I can work on it all I want, without
worrying about backward compatibility.
Finally, Perl is said to be a language for system administration.
Could it really be the case that Perl isn't up to the task of building
and installing software? Even if that software is a bunch of stupid
little .pm files that just need to be copied from one place to
another? My sense was that we could design a system to accomplish
this in a flexible, extensible, and friendly manner. Or die trying.
The current method of relying on time stamps to determine whether a
derived file is out of date isn't likely to scale well, since it
requires tracing all dependencies backward, it runs into problems on
NFS, and it's just generally flimsy. It would be better to use an MD5
signature or the like, if available. See cons
for an example.
- - append to perllocal.pod
- - add a 'plugin' functionality
Ken Williams <kwilliams@cpan.org>
Development questions, bug reports, and patches should be sent to the Module-Build mailing list at <module-build@perl.org>.
Bug reports are also welcome at <http://rt.cpan.org/NoAuth/Bugs.html?Dist=Module-Build>.
The latest development version is available from the Subversion repository at <https://svn.perl.org/modules/Module-Build/trunk/>
Copyright (c) 2001-2006 Ken Williams. All rights reserved.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
perl(1), Module::Build::Cookbook, Module::Build::Authoring, Module::Build::API, ExtUtils::MakeMaker, YAML::Tiny
META.yml Specification: http://module-build.sourceforge.net/META-spec-current.html