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https://github.com/perlalien/alien-build
Build external dependencies for use in CPAN
https://github.com/perlalien/alien-build
alien cpan perl
Last synced: 2 months ago
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Build external dependencies for use in CPAN
- Host: GitHub
- URL: https://github.com/perlalien/alien-build
- Owner: PerlAlien
- Created: 2017-01-18T15:09:59.000Z (about 8 years ago)
- Default Branch: main
- Last Pushed: 2024-06-05T21:07:15.000Z (8 months ago)
- Last Synced: 2024-06-18T11:08:28.724Z (7 months ago)
- Topics: alien, cpan, perl
- Language: Perl
- Homepage:
- Size: 3.33 MB
- Stars: 16
- Watchers: 10
- Forks: 25
- Open Issues: 45
-
Metadata Files:
- Readme: README.md
- Changelog: Changes
- Support: SUPPORT
Awesome Lists containing this project
README
# Alien::Build     
Build external dependencies for use in CPAN
# SYNOPSIS
```perl
my $build = Alien::Build->load('./alienfile');
$build->load_requires('configure');
$build->set_prefix('/usr/local');
$build->set_stage('/foo/mystage'); # needs to be absolute
$build->load_requires($build->install_type);
$build->download;
$build->build;
# files are now in /foo/mystage, it is your job (or
# ExtUtils::MakeMaker, Module::Build, etc) to copy
# those files into /usr/local
```
# DESCRIPTION
This module provides tools for building external (non-CPAN) dependencies
for CPAN. It is mainly designed to be used at install time of a CPAN
client, and work closely with [Alien::Base](https://metacpan.org/pod/Alien::Base) which is used at runtime.
This is the detailed documentation for the [Alien::Build](https://metacpan.org/pod/Alien::Build) class.
If you are starting out you probably want to do so from one of these documents:
- [Alien::Build::Manual::Alien](https://metacpan.org/pod/Alien::Build::Manual::Alien)
A broad overview of `Alien-Build` and its ecosystem.
- [Alien::Build::Manual::AlienUser](https://metacpan.org/pod/Alien::Build::Manual::AlienUser)
For users of an `Alien::libfoo` that is implemented using [Alien::Base](https://metacpan.org/pod/Alien::Base).
(The developer of `Alien::libfoo` _should_ provide the documentation
necessary, but if not, this is the place to start).
- [Alien::Build::Manual::AlienAuthor](https://metacpan.org/pod/Alien::Build::Manual::AlienAuthor)
If you are writing your own [Alien](https://metacpan.org/pod/Alien) based on [Alien::Build](https://metacpan.org/pod/Alien::Build) and [Alien::Base](https://metacpan.org/pod/Alien::Base).
- [Alien::Build::Manual::FAQ](https://metacpan.org/pod/Alien::Build::Manual::FAQ)
If you have a common question that has already been answered, like
"How do I use [alienfile](https://metacpan.org/pod/alienfile) with some build system".
- [Alien::Build::Manual::PluginAuthor](https://metacpan.org/pod/Alien::Build::Manual::PluginAuthor)
This is for the brave souls who want to write plugins that will work with
[Alien::Build](https://metacpan.org/pod/Alien::Build) + [alienfile](https://metacpan.org/pod/alienfile).
- [Alien::Build::Manual::Security](https://metacpan.org/pod/Alien::Build::Manual::Security)
If you are concerned that [Alien](https://metacpan.org/pod/Alien)s might be downloading tarballs off
the internet, then this is the place for you. This will discuss some
of the risks of downloading (really any) software off the internet
and will give you some tools to remediate these risks.
Note that you will not usually create a [Alien::Build](https://metacpan.org/pod/Alien::Build) instance
directly, but rather be using a thin installer layer, such as
[Alien::Build::MM](https://metacpan.org/pod/Alien::Build::MM) (for use with [ExtUtils::MakeMaker](https://metacpan.org/pod/ExtUtils::MakeMaker)) or
[Alien::Build::MB](https://metacpan.org/pod/Alien::Build::MB) (for use with [Module::Build](https://metacpan.org/pod/Module::Build)). One of the
goals of this project is to remain installer agnostic.
# CONSTRUCTORS
## new
```perl
my $build = Alien::Build->new;
```
This creates a new empty instance of [Alien::Build](https://metacpan.org/pod/Alien::Build). Normally you will
want to use `load` below to create an instance of [Alien::Build](https://metacpan.org/pod/Alien::Build) from
an [alienfile](https://metacpan.org/pod/alienfile) recipe.
## load
```perl
my $build = Alien::Build->load($alienfile);
```
This creates an [Alien::Build](https://metacpan.org/pod/Alien::Build) instance with the given [alienfile](https://metacpan.org/pod/alienfile)
recipe.
## resume
```perl
my $build = Alien::Build->resume($alienfile, $root);
```
Load a checkpointed [Alien::Build](https://metacpan.org/pod/Alien::Build) instance. You will need the original
[alienfile](https://metacpan.org/pod/alienfile) and the build root (usually `_alien`), and a build that
had been properly checkpointed using the `checkpoint` method below.
# PROPERTIES
There are three main properties for [Alien::Build](https://metacpan.org/pod/Alien::Build). There are a number
of properties documented here with a specific usage. Note that these
properties may need to be serialized into something primitive like JSON
that does not support: regular expressions, code references of blessed
objects.
If you are writing a plugin ([Alien::Build::Plugin](https://metacpan.org/pod/Alien::Build::Plugin)) you should use a
prefix like "plugin\__name_" (where _name_ is the name of your plugin)
so that it does not interfere with other plugin or future versions of
[Alien::Build](https://metacpan.org/pod/Alien::Build). For example, if you were writing
`Alien::Build::Plugin::Fetch::NewProtocol`, please use the prefix
`plugin_fetch_newprotocol`:
```perl
sub init
{
my($self, $meta) = @_;
$meta->prop( plugin_fetch_newprotocol_foo => 'some value' );
$meta->register_hook(
some_hook => sub {
my($build) = @_;
$build->install_prop->{plugin_fetch_newprotocol_bar} = 'some other value';
$build->runtime_prop->{plugin_fetch_newprotocol_baz} = 'and another value';
}
);
}
```
If you are writing a [alienfile](https://metacpan.org/pod/alienfile) recipe please use the prefix `my_`:
```perl
use alienfile;
meta_prop->{my_foo} = 'some value';
probe sub {
my($build) = @_;
$build->install_prop->{my_bar} = 'some other value';
$build->install_prop->{my_baz} = 'and another value';
};
```
Any property may be used from a command:
```perl
probe [ 'some command %{.meta.plugin_fetch_newprotocol_foo}' ];
probe [ 'some command %{.install.plugin_fetch_newprotocol_bar}' ];
probe [ 'some command %{.runtime.plugin_fetch_newprotocol_baz}' ];
probe [ 'some command %{.meta.my_foo}' ];
probe [ 'some command %{.install.my_bar}' ];
probe [ 'some command %{.runtime.my_baz}' ];
```
## meta\_prop
```perl
my $href = $build->meta_prop;
my $href = Alien::Build->meta_prop;
```
Meta properties have to do with the recipe itself, and not any particular
instance that probes or builds that recipe. Meta properties can be changed
from within an [alienfile](https://metacpan.org/pod/alienfile) using the `meta_prop` directive, or from
a plugin from its `init` method (though should NOT be modified from any
hooks registered within that `init` method). This is not strictly enforced,
but if you do not follow this rule your recipe will likely be broken.
- arch
This is a hint to an installer like [Alien::Build::MM](https://metacpan.org/pod/Alien::Build::MM) or [Alien::Build::MB](https://metacpan.org/pod/Alien::Build::MB),
that the library or tool contains architecture dependent files and so should
be stored in an architecture dependent location. If not specified by your
[alienfile](https://metacpan.org/pod/alienfile) then it will be set to true.
- check\_digest
True if cryptographic digest should be checked when files are fetched
or downloaded. This is set by
[Digest negotiator plugin](https://metacpan.org/pod/Alien::Build::Plugin::Digest::Negotiate).
- destdir
Some plugins ([Alien::Build::Plugin::Build::Autoconf](https://metacpan.org/pod/Alien::Build::Plugin::Build::Autoconf) for example) support
installing via `DESTDIR`. They will set this property to true if they
plan on doing such an install. This helps [Alien::Build](https://metacpan.org/pod/Alien::Build) find the staged
install files and how to locate them.
If available, `DESTDIR` is used to stage install files in a sub directory before
copying the files into `blib`. This is generally preferred method
if available.
- destdir\_filter
Regular expression for the files that should be copied from the `DESTDIR`
into the stage directory. If not defined, then all files will be copied.
- destdir\_ffi\_filter
Same as `destdir_filter` except applies to `build_ffi` instead of `build`.
- digest
This properties contains the cryptographic digests (if any) that should
be used when verifying any fetched and downloaded files. It is a hash
reference where the key is the filename and the value is an array
reference containing a pair of values, the first being the algorithm
('SHA256' is recommended) and the second is the actual digest. The
special filename `*` may be specified to indicate that any downloaded
file should match that digest. If there are both real filenames and
the `*` placeholder, the real filenames will be used for filenames
that match and any other files will use the placeholder. Example:
```perl
$build->meta_prop->{digest} = {
'foo-1.00.tar.gz' => [ SHA256 => '9feac593aa49a44eb837de52513a57736457f1ea70078346c60f0bfc5f24f2c1' ],
'foo-1.01.tar.gz' => [ SHA256 => '6bbde6a7f10ae5924cf74afc26ff5b7bc4b4f9dfd85c6b534c51bd254697b9e7' ],
'*' => [ SHA256 => '33a20aae3df6ecfbe812b48082926d55391be4a57d858d35753ab1334b9fddb3' ],
};
```
Cryptographic signatures will only be checked
if the [check\_digest meta property](#check_digest) is set and if the
[Digest negotiator plugin](https://metacpan.org/pod/Alien::Build::Plugin::Digest::Negotiate) is loaded.
(The Digest negotiator can be used directly, but is also loaded automatically
if you use the [digest directive](https://metacpan.org/pod/alienfile#digest) is used by the [alienfile](https://metacpan.org/pod/alienfile)).
- env
Environment variables to override during the build stage.
- env\_interpolate
Environment variable values will be interpolated with helpers. Example:
```
meta->prop->{env_interpolate} = 1;
meta->prop->{env}->{PERL} = '%{perl}';
```
- local\_source
Set to true if source code package is available locally. (that is not fetched
over the internet). This is computed by default based on the `start_url`
property. Can be set by an [alienfile](https://metacpan.org/pod/alienfile) or plugin.
- platform
Hash reference. Contains information about the platform beyond just `$^O`.
- platform.compiler\_type
Refers to the type of flags that the compiler accepts. May be expanded in the
future, but for now, will be one of:
- microsoft
On Windows when using Microsoft Visual C++
- unix
Virtually everything else, including gcc on windows.
The main difference is that with Visual C++ `-LIBPATH` should be used instead
of `-L`, and static libraries should have the `.LIB` suffix instead of `.a`.
- platform.system\_type
`$^O` is frequently good enough to make platform specific logic in your
[alienfile](https://metacpan.org/pod/alienfile), this handles the case when $^O can cover platforms that provide
multiple environments that Perl might run under. The main example is windows,
but others may be added in the future.
- unix
- vms
- windows-activestate
- windows-microsoft
- windows-mingw
- windows-strawberry
- windows-unknown
Note that `cygwin` and `msys` are considered `unix` even though they run
on windows!
- platform.cpu.count
Contains a non-negative integer of available (possibly virtual) CPUs on the
system. This can be used by build plugins to build in parallel. The environment
variable `ALIEN_CPU_COUNT` can be set to override the CPU count.
- platform.cpu.arch.name
Contains a normalized name for the architecture of the current Perl. This can
be used by fetch plugins to determine which binary packages to download.
The value may be one of the following, but this list will be expanded as
needed.
- `armel`
32-bit ARM soft-float
- `armhf`
32-bit ARM hard-float
- `aarch64`
64-bit ARM
- `ppc`
32-bit PowerPC (big-endian)
- `ppc64`
64-bit PowerPC (big-endian)
- `x86`
32-bit Intel (i386, i486, i686)
- `x86_64`
64-bit Intel (AMD64)
- `unknown`
Unable to detect architecture. Please report this if needed.
- out\_of\_source
Build in a different directory from the where the source code is stored.
In autoconf this is referred to as a "VPATH" build. Everyone else calls this
an "out-of-source" build. When this property is true, instead of extracting
to the source build root, the downloaded source will be extracted to an source
extraction directory and the source build root will be empty. You can use the
`extract` install property to get the location of the extracted source.
- network
True if a network fetch is available. This should NOT be set by an [alienfile](https://metacpan.org/pod/alienfile)
or plugin. This is computed based on the `ALIEN_INSTALL_NETWORK` environment
variables.
- start\_url
The default or start URL used by fetch plugins.
## install\_prop
```perl
my $href = $build->install_prop;
```
Install properties are used during the install phase (either
under `share` or `system` install). They are remembered for
the entire install phase, but not kept around during the runtime
phase. Thus they cannot be accessed from your [Alien::Base](https://metacpan.org/pod/Alien::Base)
based module.
- autoconf\_prefix
The prefix as understood by autoconf. This is only different on Windows
Where MSYS is used and paths like `C:/foo` are represented as `/C/foo`
which are understood by the MSYS tools, but not by Perl. You should
only use this if you are using [Alien::Build::Plugin::Build::Autoconf](https://metacpan.org/pod/Alien::Build::Plugin::Build::Autoconf) in
your [alienfile](https://metacpan.org/pod/alienfile). This is set during before the
[build hook](https://metacpan.org/pod/Alien::Build::Manual::PluginAuthor#build-hook) is run.
- download
The location of the downloaded archive (tar.gz, or similar) or directory.
This will be undefined until the archive is actually downloaded.
- download\_detail
This property contains optional details about a downloaded file. This
property is populated by [Alien::Build](https://metacpan.org/pod/Alien::Build) core. This property is a
hash reference. The key is the path to the file that has been downloaded
and the value is a hash reference with additional detail. All fields
are optional.
- download\_detail.digest
This, if available, with the cryptographic signature that was successfully
matched against the downloaded file. It is an array reference with a
pair of values, the algorithm (typically something like `SHA256`) and
the digest.
- download\_detail.protocol
This, if available, will be the URL protocol used to fetch the downloaded
file.
- env
Environment variables to override during the build stage. Plugins are
free to set additional overrides using this hash.
- extract
The location of the last source extraction. For a "out-of-source" build
(see the `out_of_source` meta property above), this will only be set once.
For other types of builds, the source code may be extracted multiple times,
and thus this property may change.
- old
\[deprecated\]
Hash containing information on a previously installed Alien of the same
name, if available. This may be useful in cases where you want to
reuse the previous install if it is still sufficient.
- old.prefix
\[deprecated\]
The prefix for the previous install. Versions prior to 1.42 unfortunately
had this in typo form of `preifx`.
- old.runtime
\[deprecated\]
The runtime properties from the previous install.
- patch
Directory with patches, if available. This will be `undef` if there
are no patches. When initially installing an alien this will usually
be a sibling of the `alienfile`, a directory called `patch`. Once
installed this will be in the share directory called `_alien/patch`.
The former is useful for rebuilding an alienized package using
[af](https://metacpan.org/pod/af).
- prefix
The install time prefix. Under a `destdir` install this is the
same as the runtime or final install location. Under a non-`destdir`
install this is the `stage` directory (usually the appropriate
share directory under `blib`).
- root
The build root directory. This will be an absolute path. It is the
absolute form of `./_alien` by default.
- stage
The stage directory where files will be copied. This is usually the
root of the blib share directory.
- system\_probe\_class
After the probe step this property may contain the plugin class that
performed the system probe. It shouldn't be filled in directly by
the plugin (instead if should use the hook property `probe_class`,
see below). This is optional, and not all probe plugins will provide
this information.
- system\_probe\_instance\_id
After the probe step this property may contain the plugin instance id that
performed the system probe. It shouldn't be filled in directly by
the plugin (instead if should use the hook property `probe_instance_id`,
see below). This is optional, and not all probe plugins will provide
this information.
## plugin\_instance\_prop
```perl
my $href = $build->plugin_instance_prop($plugin);
```
This returns the private plugin instance properties for a given plugin.
This method should usually only be called internally by plugins themselves
to keep track of internal state. Because the content can be used arbitrarily
by the owning plugin because it is private to the plugin, and thus is not
part of the [Alien::Build](https://metacpan.org/pod/Alien::Build) spec.
## runtime\_prop
```perl
my $href = $build->runtime_prop;
```
Runtime properties are used during the install and runtime phases
(either under `share` or `system` install). This should include
anything that you will need to know to use the library or tool
during runtime, and shouldn't include anything that is no longer
relevant once the install process is complete.
- alien\_build\_version
The version of [Alien::Build](https://metacpan.org/pod/Alien::Build) used to install the library or tool.
- alt
Alternate configurations. If the alienized package has multiple
libraries this could be used to store the different compiler or
linker flags for each library. Typically this will be set by a
plugin in the gather stage (for either share or system installs).
- cflags
The compiler flags. This is typically set by a plugin in the
gather stage (for either share or system installs).
- cflags\_static
The static compiler flags. This is typically set by a plugin in the
gather stage (for either share or system installs).
- command
The command name for tools where the name my differ from platform to
platform. For example, the GNU version of make is usually `make` in
Linux and `gmake` on FreeBSD. This is typically set by a plugin in the
gather stage (for either share or system installs).
- ffi\_name
The name DLL or shared object "name" to use when searching for dynamic
libraries at runtime. This is passed into [FFI::CheckLib](https://metacpan.org/pod/FFI::CheckLib), so if
your library is something like `libarchive.so` or `archive.dll` you
would set this to `archive`. This may be a string or an array of
strings. This is typically set by a plugin in the gather stage
(for either share or system installs).
- ffi\_checklib
This property contains two sub properties:
- ffi\_checklib.share
```
$build->runtime_prop->{ffi_checklib}->{share} = [ ... ];
```
Array of additional [FFI::CheckLib](https://metacpan.org/pod/FFI::CheckLib) flags to pass in to `find_lib`
for a `share` install.
- ffi\_checklib.system
Array of additional [FFI::CheckLib](https://metacpan.org/pod/FFI::CheckLib) flags to pass in to `find_lib`
for a `system` install.
Among other things, useful for specifying the `try_linker_script`
flag:
```perl
$build->runtime_prop->{ffi_checklib}->{system} = [ try_linker_script => 1 ];
```
This is typically set by a plugin in the gather stage
(for either share or system installs).
- inline\_auto\_include
\[version 2.53\]
This property is an array reference of C code that will be passed into
[Inline::C](https://metacpan.org/pod/Inline::C) to make sure that appropriate headers are automatically
included. See ["auto\_include" in Inline::C](https://metacpan.org/pod/Inline::C#auto_include) for details.
- install\_type
The install type. This is set by AB core after the
[probe hook](https://metacpan.org/pod/Alien::Build::Manual::PluginAuthor#probe-hook) is
executed. Is one of:
- system
For when the library or tool is provided by the operating system, can be
detected by [Alien::Build](https://metacpan.org/pod/Alien::Build), and is considered satisfactory by the
`alienfile` recipe.
- share
For when a system install is not possible, the library source will be
downloaded from the internet or retrieved in another appropriate fashion
and built.
- libs
The library flags. This is typically set by a plugin in the
gather stage (for either share or system installs).
- libs\_static
The static library flags. This is typically set by a plugin in the
gather stage (for either share or system installs).
- perl\_module\_version
The version of the Perl module used to install the alien (if available).
For example if [Alien::curl](https://metacpan.org/pod/Alien::curl) is installing `libcurl` this would be the
version of [Alien::curl](https://metacpan.org/pod/Alien::curl) used during the install step.
- prefix
The final install root. This is usually they share directory.
- version
The version of the library or tool. This is typically set by a plugin in the
gather stage (for either share or system installs).
## hook\_prop
```perl
my $href = $build->hook_prop;
```
Hook properties are for the currently running (if any) hook. They are
used only during the execution of each hook and are discarded after.
If no hook is currently running then `hook_prop` will return `undef`.
- name
The name of the currently running hook.
- version (probe)
Probe and PkgConfig plugins _may_ set this property indicating the
version of the alienized package. Not all plugins and configurations
may be able to provide this.
- probe\_class (probe)
Probe and PkgConfig plugins _may_ set this property indicating the
plugin class that made the probe. If the probe results in a system
install this will be propagated to `system_probe_class` for later
use.
- probe\_instance\_id (probe)
Probe and PkgConfig plugins _may_ set this property indicating the
plugin instance id that made the probe. If the probe results in a
system install this will be propagated to `system_probe_instance_id`
for later use.
# METHODS
## checkpoint
```
$build->checkpoint;
```
Save any install or runtime properties so that they can be reloaded on
a subsequent run in a separate process. This is useful if your build
needs to be done in multiple stages from a `Makefile`, such as with
[ExtUtils::MakeMaker](https://metacpan.org/pod/ExtUtils::MakeMaker). Once checkpointed you can use the `resume`
constructor (documented above) to resume the probe/build/install\]
process.
## root
```perl
my $dir = $build->root;
```
This is just a shortcut for:
```perl
my $root = $build->install_prop->{root};
```
Except that it will be created if it does not already exist.
## install\_type
```perl
my $type = $build->install_type;
```
This will return the install type. (See the like named install property
above for details). This method will call `probe` if it has not already
been called.
## is\_system\_install
```perl
my $boolean = $build->is_system_install;
```
Returns true if the alien is a system install type.
## is\_share\_install
```perl
my $boolean = $build->is_share_install;
```
Returns true if the alien is a share install type.
## download\_rule
```perl
my $rule = $build->download_rule;
```
This returns install rule as a string. This is determined by the environment
and should be one of:
- `warn`
Warn only if fetching via non secure source (secure sources include `https`,
and bundled files, may include other encrypted protocols in the future).
- `digest`
Require that any downloaded source package have a cryptographic signature in
the [alienfile](https://metacpan.org/pod/alienfile) and that signature matches what was downloaded.
- `encrypt`
Require that any downloaded source package is fetched via secure source.
- `digest_or_encrypt`
Require that any downloaded source package is **either** fetched via a secure source
**or** has a cryptographic signature in the [alienfile](https://metacpan.org/pod/alienfile) and that signature matches
what was downloaded.
- `digest_and_encrypt`
Require that any downloaded source package is **both** fetched via a secure source
**and** has a cryptographic signature in the [alienfile](https://metacpan.org/pod/alienfile) and that signature matches
what was downloaded.
The current default is `warn`, but in the near future this will be upgraded to
`digest_or_encrypt`.
## set\_prefix
```
$build->set_prefix($prefix);
```
Set the final (unstaged) prefix. This is normally only called by [Alien::Build::MM](https://metacpan.org/pod/Alien::Build::MM)
and similar modules. It is not intended for use from plugins or from an [alienfile](https://metacpan.org/pod/alienfile).
## set\_stage
```
$build->set_stage($dir);
```
Sets the stage directory. This is normally only called by [Alien::Build::MM](https://metacpan.org/pod/Alien::Build::MM)
and similar modules. It is not intended for use from plugins or from an [alienfile](https://metacpan.org/pod/alienfile).
## requires
```perl
my $hash = $build->requires($phase);
```
Returns a hash reference of the modules required for the given phase. Phases
include:
- configure
These modules must already be available when the [alienfile](https://metacpan.org/pod/alienfile) is read.
- any
These modules are used during either a `system` or `share` install.
- share
These modules are used during the build phase of a `share` install.
- system
These modules are used during the build phase of a `system` install.
## load\_requires
```
$build->load_requires($phase);
```
This loads the appropriate modules for the given phase (see `requires` above
for a description of the phases).
## probe
```perl
my $install_type = $build->probe;
```
Attempts to determine if the operating system has the library or
tool already installed. If so, then the string `system` will
be returned and a system install will be performed. If not,
then the string `share` will be installed and the tool or
library will be downloaded and built from source.
If the environment variable `ALIEN_INSTALL_TYPE` is set, then that
will force a specific type of install. If the detection logic
cannot accommodate the install type requested then it will fail with
an exception.
## download
```
$build->download;
```
Download the source, usually as a tarball, usually from the internet.
Under a `system` install this does not do anything.
## fetch
```perl
my $res = $build->fetch;
my $res = $build->fetch($url, %options);
```
Fetch a resource using the fetch hook. Returns the same hash structure
described below in the
[fetch hook](https://metacpan.org/pod/Alien::Build::Manual::PluginAuthor#fetch-hook) documentation.
\[version 2.39\]
As of [Alien::Build](https://metacpan.org/pod/Alien::Build) 2.39, these options are supported:
- http\_headers
```perl
my $res = $build->fetch($url, http_headers => [ $key1 => $value1, $key2 => $value 2, ... ]);
```
Set the HTTP request headers on all outgoing HTTP requests. Note that not all
protocols or fetch plugins support setting request headers, but the ones that
do not _should_ issue a warning if you try to set request headers and they
are not supported.
## check\_digest
\[experimental\]
```perl
my $bool = $build->check_digest($path);
```
Checks any cryptographic signatures for the given file. The
file is specified by `$path` which may be one of:
- string
Containing the path to the file to be checked.
- [Path::Tiny](https://metacpan.org/pod/Path::Tiny)
Containing the path to the file to be checked.
- `HASH`
A Hash reference containing information about a file. See
the [fetch hook](https://metacpan.org/pod/Alien::Build::Manual::PluginAuthor#fetch-hook) for details
on the format.
Returns true if the cryptographic signature matches, false if cryptographic
signatures are disabled. Will throw an exception if the signature does not
match, or if no plugin provides the correct algorithm for checking the
signature.
## decode
```perl
my $decoded_res = $build->decode($res);
```
Decode the HTML or file listing returned by `fetch`. Returns the same
hash structure described below in the
[decode hook](https://metacpan.org/pod/Alien::Build::Manual::PluginAuthor#decode-hook) documentation.
## prefer
```perl
my $sorted_res = $build->prefer($res);
```
Filter and sort candidates. The preferred candidate will be returned first in the list.
The worst candidate will be returned last. Returns the same hash structure described
below in the
[prefer hook](https://metacpan.org/pod/Alien::Build::Manual::PluginAuthor#prefer-hook) documentation.
## extract
```perl
my $dir = $build->extract;
my $dir = $build->extract($archive);
```
Extracts the given archive into a fresh directory. This is normally called internally
to [Alien::Build](https://metacpan.org/pod/Alien::Build), and for normal usage is not needed from a plugin or [alienfile](https://metacpan.org/pod/alienfile).
## build
```
$build->build;
```
Run the build step. It is expected that `probe` and `download`
have already been performed. What it actually does depends on the
type of install:
- share
The source is extracted, and built as determined by the [alienfile](https://metacpan.org/pod/alienfile)
recipe. If there is a `gather_share` that will be executed last.
- system
The
[gather\_system hook](https://metacpan.org/pod/Alien::Build::Manual::PluginAuthor#gather_system-hook)
will be executed.
## test
```
$build->test;
```
Run the test phase
## clean\_install
```
$build->clean_install
```
Clean files from the final install location. The default implementation removes all
files recursively except for the `_alien` directory. This is helpful when you have
an old install with files that may break the new build.
For a non-share install this doesn't do anything.
## system
```
$build->system($command);
$build->system($command, @args);
```
Interpolates the command and arguments and run the results using
the Perl `system` command.
## log
```
$build->log($message);
```
Send a message to the log. By default this prints to `STDOUT`.
## meta
```perl
my $meta = Alien::Build->meta;
my $meta = $build->meta;
```
Returns the meta object for your [Alien::Build](https://metacpan.org/pod/Alien::Build) class or instance. The
meta object is a way to manipulate the recipe, and so any changes to the
meta object should be made before the `probe`, `download` or `build` steps.
# META METHODS
## prop
```perl
my $href = $build->meta->prop;
```
Meta properties. This is the same as calling `meta_prop` on
the class or [Alien::Build](https://metacpan.org/pod/Alien::Build) instance.
## add\_requires
```perl
Alien::Build->meta->add_requires($phase, $module => $version, ...);
```
Add the requirement to the given phase. Phase should be one of:
- configure
- any
- share
- system
## interpolator
```perl
my $interpolator = $build->meta->interpolator;
my $interpolator = Alien::Build->interpolator;
```
Returns the [Alien::Build::Interpolate](https://metacpan.org/pod/Alien::Build::Interpolate) instance for the [Alien::Build](https://metacpan.org/pod/Alien::Build) class.
## has\_hook
```perl
my $bool = $build->meta->has_hook($name);
my $bool = Alien::Build->has_hook($name);
```
Returns if there is a usable hook registered with the given name.
## register\_hook
```
$build->meta->register_hook($name, $instructions);
Alien::Build->meta->register_hook($name, $instructions);
```
Register a hook with the given name. `$instruction` should be either
a code reference, or a command sequence, which is an array reference.
## default\_hook
```
$build->meta->default_hook($name, $instructions);
Alien::Build->meta->default_hook($name, $instructions);
```
Register a default hook, which will be used if the [alienfile](https://metacpan.org/pod/alienfile) does not
register its own hook with that name.
## around\_hook
```
$build->meta->around_hook($hook_name, $code);
Alien::Build->meta->around_hook($hook_name, $code);
```
Wrap the given hook with a code reference. This is similar to a [Moose](https://metacpan.org/pod/Moose)
method modifier, except that it wraps around the given hook instead of
a method. For example, this will add a probe system requirement:
```perl
$build->meta->around_hook(
probe => sub {
my $orig = shift;
my $build = shift;
my $type = $orig->($build, @_);
return $type unless $type eq 'system';
# also require a configuration file
if(-f '/etc/foo.conf')
{
return 'system';
}
else
{
return 'share';
}
},
);
```
## after\_hook
```perl
$build->meta->after_hook($hook_name, sub {
my(@args) = @_;
...
});
```
Execute the given code reference after the hook. The original
arguments are passed into the code reference.
## before\_hook
```perl
$build->meta->before_hook($hook_name, sub {
my(@args) = @_;
...
});
```
Execute the given code reference before the hook. The original
arguments are passed into the code reference.
## apply\_plugin
```
Alien::Build->meta->apply_plugin($name);
Alien::Build->meta->apply_plugin($name, @args);
```
Apply the given plugin with the given arguments.
# ENVIRONMENT
[Alien::Build](https://metacpan.org/pod/Alien::Build) responds to these environment variables:
- ALIEN\_BUILD\_LOG
The default log class used. See [Alien::Build::Log](https://metacpan.org/pod/Alien::Build::Log) and [Alien::Build::Log::Default](https://metacpan.org/pod/Alien::Build::Log::Default).
- ALIEN\_BUILD\_PKG\_CONFIG
Override the logic in [Alien::Build::Plugin::PkgConfig::Negotiate](https://metacpan.org/pod/Alien::Build::Plugin::PkgConfig::Negotiate) which
chooses the best `pkg-config` plugin.
- ALIEN\_BUILD\_POSTLOAD
semicolon separated list of plugins to automatically load after parsing
your [alienfile](https://metacpan.org/pod/alienfile).
- ALIEN\_BUILD\_PRELOAD
semicolon separated list of plugins to automatically load before parsing
your [alienfile](https://metacpan.org/pod/alienfile).
- ALIEN\_BUILD\_RC
Perl source file which can override some global defaults for [Alien::Build](https://metacpan.org/pod/Alien::Build),
by, for example, setting preload and postload plugins.
- ALIEN\_DOWNLOAD\_RULE
This value determines the rules by which types of downloads are allowed. The legal
values listed under ["download\_rule"](#download_rule), plus `default` which will be the default for
the current version of [Alien::Build](https://metacpan.org/pod/Alien::Build). For this version that default is `warn`.
- ALIEN\_INSTALL\_NETWORK
If set to true (the default), then network fetch will be allowed. If set to
false, then network fetch will not be allowed.
What constitutes a local vs. network fetch is determined based on the `start_url`
and `local_source` meta properties. An [alienfile](https://metacpan.org/pod/alienfile) or plugin `could` override
this detection (possibly inappropriately), so this variable is not a substitute
for properly auditing of Perl modules for environments that require that.
- ALIEN\_INSTALL\_TYPE
If set to `share` or `system`, it will override the system detection logic.
If set to `default`, it will use the default setting for the [alienfile](https://metacpan.org/pod/alienfile).
The behavior of other values is undefined.
Although the recommended way for a consumer to use an [Alien::Base](https://metacpan.org/pod/Alien::Base) based [Alien](https://metacpan.org/pod/Alien)
is to declare it as a static configure and build-time dependency, some consumers
may prefer to fallback on using an [Alien](https://metacpan.org/pod/Alien) only when the consumer itself cannot
detect the necessary package. In some cases the consumer may want the user to opt-in
to using an [Alien](https://metacpan.org/pod/Alien) before requiring it.
To keep the interface consistent among Aliens, the consumer of the fallback opt-in
[Alien](https://metacpan.org/pod/Alien) may fallback on the [Alien](https://metacpan.org/pod/Alien) if the environment variable `ALIEN_INSTALL_TYPE`
is set to any value. The rationale is that by setting this environment variable the
user is aware that [Alien](https://metacpan.org/pod/Alien) modules may be installed and have indicated consent.
The actual implementation of this, by its nature would have to be in the consuming
CPAN module.
- DESTDIR
This environment variable will be manipulated during a destdir install.
- PKG\_CONFIG
This environment variable can be used to override the program name for `pkg-config`
when using the command line plugin: [Alien::Build::Plugin::PkgConfig::CommandLine](https://metacpan.org/pod/Alien::Build::Plugin::PkgConfig::CommandLine).
- ftp\_proxy, all\_proxy
If these environment variables are set, it may influence the Download negotiation
plugin [Alien::Build::Plugin::Download::Negotiate](https://metacpan.org/pod/Alien::Build::Plugin::Download::Negotiate). Other proxy variables may
be used by some Fetch plugins, if they support it.
# SUPPORT
The intent of the `Alien-Build` team is to support the same versions of
Perl that are supported by the Perl toolchain. As of this writing that
means 5.16 and better.
Please feel encouraged to report issues that you encounter to the
project GitHub Issue tracker:
- [https://github.com/PerlAlien/Alien-Build/issues](https://github.com/PerlAlien/Alien-Build/issues)
Better if you can fix the issue yourself, please feel encouraged to open
pull-request on the project GitHub:
- [https://github.com/PerlAlien/Alien-Build/pulls](https://github.com/PerlAlien/Alien-Build/pulls)
If you are confounded and have questions, join us on the `#native`
channel on irc.perl.org. The `Alien-Build` developers frequent this
channel and can probably help point you in the right direction. If you
don't have an IRC client handy, you can use this web interface:
- [https://chat.mibbit.com/?channel=%23native&server=irc.perl.org](https://chat.mibbit.com/?channel=%23native&server=irc.perl.org)
# SEE ALSO
[Alien::Build::Manual::AlienAuthor](https://metacpan.org/pod/Alien::Build::Manual::AlienAuthor),
[Alien::Build::Manual::AlienUser](https://metacpan.org/pod/Alien::Build::Manual::AlienUser),
[Alien::Build::Manual::Contributing](https://metacpan.org/pod/Alien::Build::Manual::Contributing),
[Alien::Build::Manual::FAQ](https://metacpan.org/pod/Alien::Build::Manual::FAQ),
[Alien::Build::Manual::PluginAuthor](https://metacpan.org/pod/Alien::Build::Manual::PluginAuthor)
[alienfile](https://metacpan.org/pod/alienfile), [Alien::Build::MM](https://metacpan.org/pod/Alien::Build::MM), [Alien::Build::Plugin](https://metacpan.org/pod/Alien::Build::Plugin), [Alien::Base](https://metacpan.org/pod/Alien::Base), [Alien](https://metacpan.org/pod/Alien)
# THANKS
[Alien::Base](https://metacpan.org/pod/Alien::Base) was originally written by Joel Berger, the rest of this project would
not have been possible without him getting the project started. Thanks to his support
I have been able to augment the original [Alien::Base](https://metacpan.org/pod/Alien::Base) system with a reliable set
of tools ([Alien::Build](https://metacpan.org/pod/Alien::Build), [alienfile](https://metacpan.org/pod/alienfile), [Test::Alien](https://metacpan.org/pod/Test::Alien)), which make up this toolset.
The original [Alien::Base](https://metacpan.org/pod/Alien::Base) is still copyright (c) 2012-2020 Joel Berger. It has
the same license as the rest of the Alien::Build and related tools distributed as
`Alien-Build`. Joel Berger thanked a number of people who helped in in the development
of [Alien::Base](https://metacpan.org/pod/Alien::Base), in the documentation for that module.
I would also like to acknowledge the other members of the PerlAlien github
organization, Zakariyya Mughal (sivoais, ZMUGHAL) and mohawk (ETJ). Also important
in the early development of [Alien::Build](https://metacpan.org/pod/Alien::Build) were the early adopters Chase Whitener
(genio, CAPOEIRAB, author of [Alien::libuv](https://metacpan.org/pod/Alien::libuv)), William N. Braswell, Jr (willthechill,
WBRASWELL, author of [Alien::JPCRE2](https://metacpan.org/pod/Alien::JPCRE2) and [Alien::PCRE2](https://metacpan.org/pod/Alien::PCRE2)) and Ahmad Fatoum (a3f,
ATHREEF, author of [Alien::libudev](https://metacpan.org/pod/Alien::libudev) and [Alien::LibUSB](https://metacpan.org/pod/Alien::LibUSB)).
The Alien ecosystem owes a debt to Dan Book, who goes by Grinnz on IRC, for answering
question about how to use [Alien::Build](https://metacpan.org/pod/Alien::Build) and friends.
# AUTHOR
Author: Graham Ollis
Contributors:
Diab Jerius (DJERIUS)
Roy Storey (KIWIROY)
Ilya Pavlov
David Mertens (run4flat)
Mark Nunberg (mordy, mnunberg)
Christian Walde (Mithaldu)
Brian Wightman (MidLifeXis)
Zaki Mughal (zmughal)
mohawk (mohawk2, ETJ)
Vikas N Kumar (vikasnkumar)
Flavio Poletti (polettix)
Salvador Fandiño (salva)
Gianni Ceccarelli (dakkar)
Pavel Shaydo (zwon, trinitum)
Kang-min Liu (劉康民, gugod)
Nicholas Shipp (nshp)
Juan Julián Merelo Guervós (JJ)
Joel Berger (JBERGER)
Petr Písař (ppisar)
Lance Wicks (LANCEW)
Ahmad Fatoum (a3f, ATHREEF)
José Joaquín Atria (JJATRIA)
Duke Leto (LETO)
Shoichi Kaji (SKAJI)
Shawn Laffan (SLAFFAN)
Paul Evans (leonerd, PEVANS)
Håkon Hægland (hakonhagland, HAKONH)
nick nauwelaerts (INPHOBIA)
Florian Weimer
# COPYRIGHT AND LICENSE
This software is copyright (c) 2011-2022 by Graham Ollis.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.