anchor.diff:  
   Package build phases
   --------------------
  -
   Building a package consist of the following phases:
   
  -`fetch`::
  +*fetch*::
       This phase downloads required sources for a `source package`, as defined by
       the `distfiles` variable or `do_fetch()` function.
   
  -`extract`::
  +*extract*::
       This phase extracts the `distfiles` files into `$wrksrc` or executes the `do_extract()`
       function, which is the directory to be used to compile the `source package`.
   
  -`configure`::
  +*configure*::
       This phase executes the `configuration` of a `source package`, i.e `GNU configure scripts`.
   
  -`build`::
  +*build*::
       This phase compiles/prepares the `source files` via `make` or any other compatible method.
   
  -`install-destdir`::
  +*install-destdir*::
       This phase installs the `package files` into a `fake destdir`, via `make install` or
       any other compatible method.
   
  -`build-pkg`::
  +*build-pkg*::
       This phase builds the `binary packages` with files stored in the `package destdir`.
   
   `xbps-src` supports running just the specified phase, and if it ran
  
positive.code: 
  The current list of available `build_style` scripts is the following:
  
  `cmake`::
      For packages that use the CMake build system, configuration arguments
      can be passed in via `configure_args`.
  
  `configure`::
      For packages that use non-GNU configure scripts, at least `--prefix=/usr`
      should be passed in via `configure_args`.
  
  `gnu-configure`::
      For packages that use GNU configure scripts, additional configuration
      arguments can be passed in via `configure_args`.
  
  `gnu-makefile`::
      For packages that use GNU make, build arguments can be passed in via
      `make_build_args` and install arguments via `make_install_args`. The build
      target can be overriden via `make_build_target` and the install target
  
  `meta`::
      For `meta-packages`, i.e packages that only install local files or simply
      depend on additional packages.
  
  `perl-ModuleBuild`::
      For packages that use the Perl
      http://search.cpan.org/~leont/Module-Build-0.4202/lib/Module/Build.pm[Module::Build] method.
  
  `perl`::
      For packages that use the Perl
      http://perldoc.perl.org/ExtUtils/MakeMaker.html[ExtUtils::MakeMaker] build method.
  
  `python-module`::
      For packages that use the Python module build method (setup.py).
  
  `waf3`::
     For packages that use the Python3 `waf` build method with python3.
  
  `waf`::
     For packages that use the Python `waf` method with python2.
  
  source section - functions
  --------------------------
  
  The following functions can be defined to change the behavior of how the
  package is downloaded, compiled and installed.
  
  `do_fetch`::
      if defined and `distfiles` is not set, use it to fetch the required sources.
  
  `do_extract`::
      if defined and `distfiles` is not set, use it to extract the required sources.
  
  `post_extract`::
      Actions to execute after `do_extract()`.
  
  `pre_configure`::
      Actions to execute after `post_extract()`.
  
  `do_configure`::
      Actions to execute to configure the package; `${configure_args}` should
      still be passed in if it's a GNU configure script.
  
  `post_configure`::
      Actions to execute after `do_configure()`.
  
  `pre_build`::
      Actions to execute after `post_configure()`.
  
  `do_build`::
      Actions to execute to build the package.
  
  `post_build`::
      Actions to execute after `do_build()`.
  
  `pre_install`::
      Actions to execute after `post_build()`.
  
  `do_install`::
      Actions to execute to install the packages files into the `fake destdir`.
  
  `post_install`::
      Actions to execute after `do_install()`.
  
  NOTE: a function defined in a template has preference over the same function
  defined by a `build_style` script.
  
negative.code: 
  Global variables
  ----------------
  The following variables are defined by `xbps-src` and can be used on any template:
  
  *makejobs*::
      Set to `-jX` if `XBPS_MAKEJOBS` is defined, to allow parallel jobs with `GNU make`.
  
  *sourcepkg*::
      Set to the to main package name, can be used to match the main package
      rather than additional binary package names.
  
  *CHROOT_READY*::
      True if the target chroot (masterdir) is ready for chroot builds.
  
  *CROSS_BUILD*::
      True if `xbps-src` is cross compiling a package.
  
  *DESTDIR*::
      Full path to the fake destdir used by the `source section`, set to
      `${XBPS_MASTERDIR}/destdir/${sourcepkg}-${version}`.
  
  *PKGDESTDIR*::
      Full path to the fake destdir used by the `pkg_install()` function in the
      `package section`, set to `${XBPS_MASTERDIR}/destdir/pkg-${pkgname}-${version}`.
  
  *XBPS_MACHINE*::
      The machine architecture as returned by `uname -m`.
  
  *XBPS_SRCDISTDIR*::
      Full path to where the `source distfiles` are stored, i.e `$XBPS_HOSTDIR/sources`.
  
  *XBPS_SRCPKGDIR*::
      Full path to the `srcpkgs` directory.
  
  *XBPS_TARGET_MACHINE*::
      The target machine architecture when cross compiling a package.
  
  
  Source section
  --------------
  Mandatory variables
  ~~~~~~~~~~~~~~~~~~~
  The list of mandatory variables in the `source section`:
  
  *homepage*::
      A string pointing to the `upstream` homepage.
  
  *license*::
      A string matching any license file available in `/usr/share/licenses`.
      Multiple licenses should be separated by commas, i.e `GPL-3, LGPL-2.1`.
  
  *maintainer*::
      A string in the form of `name <user@domain>`.
  
  *pkgname*::
      A string with the package name, matching `srcpkgs/<pkgname>`.
  
  *revision*::
      A number that must be set to 1 when the `source package` is created, or
      updated to a new `upstream version`. This should only be increased when
      the generated `binary packages` have been modified.
  
  *short_desc*::
      A string with a brief description for this package. Max 72 chars.
  
  *version*::
      A string with the package version. Must not contain dashes and at least
      one digit is required.
  
  
  Optional variables
  ~~~~~~~~~~~~~~~~~~
  *hostmakedepends*::
      The list of `host` dependencies required to build the package. Dependencies
      can be specified with the following version comparators: `<`, `>`, `<=`, `>=`
      or `foo-1.0_1` to match an exact version. If version comparator is not
      defined (just a package name), the version comparator is automatically set to `>=0`.
      Example `hostmakedepends="foo blah<1.0"`.
  
  *makedepends*::
      The list of `target` dependencies required to build the package. Dependencies
      can be specified with the following version comparators: `<`, `>`, `<=`, `>=`
      or `foo-1.0_1` to match an exact version. If version comparator is not
      defined (just a package name), the version comparator is automatically set to `>=0`.
      Example `makedepends="foo blah>=1.0"`.
  
  *bootstrap*::
      If enabled the source package is considered to be part of the `bootstrap`
      process and required to be able to build packages in the chroot. Only a
      small number of packages must set this property.
  
  *distfiles*::
      The full URL to the `upstream` source distribution files. Multiple files
      can be separated by blanks. The files must end in `.tar.lzma`, `.tar.xz`,
      `.txz`, `.tar.bz2`, `.tbz`, `.tar.gz`, `.tgz`, `.gz`, `.bz2`, `.tar` or
      `.zip`. Example `distfiles="http://foo.org/foo-1.0.tar.gz"`
  
  *checksum*::
      The `sha256` digests matching `${distfiles}`. Multiple files can be
      separated by blanks. Please note that the order must be the same than
      was used in `${distfiles}`. Example `checksum="kkas00xjkjas"`
  
  *long_desc*::
     A long description of the main package. Max 80 chars per line and must
     not contain the following characters: `&`, `<`, `>`.
  
  *wrksrc*::
      The directory name where the package sources are extracted, by default
      set to `${pkgname}-${version}`.
  
  *build_wrksrc*::
      A directory relative to `${wrksrc}` that will be used when building the package.
  
  *create_wrksrc*::
      Enable it to create the `${wrksrc}` directory. Required if a package
      contains multiple `distfiles`.
  
  *only_for_archs*::
      This expects a separated list of architectures where the package can be
      built matching `uname -m` output. Example `only_for_archs="x86_64 armv6l"`
  
  *build_style*::
      This specifies the `build method` for a package. Read below to know more
      about the available package `build methods`. If `build_style` is not set,
      the package must define at least a `do_install()` function, and optionally
      more build phases as such `do_configure()`, `do_build()`, etc.
  
  *create_srcdir*::
      This creates a directory in `${XBPS_SRCDISTDIR}` as such `${pkgname}-${version}`
      to store the package sources at the `extract` phase. Required in packages that
      use unversioned ${distfiles}`.
  
  *configure_script*::
      The name of the `configure` script to execute at the `configure` phase if
      `${build_style}` is set to `configure` or `gnu-configure` build methods.
      By default set to `./configure`.
  
  *configure_args*::
      The arguments to be passed in to the `configure` script if `${build_style}`
      is set to `configure` or `gnu-configure` build methods. By default, prefix
      must be set to `/usr`. In `gnu-configure` packages, some options are already
      set by default: `--prefix=/usr --sysconfdir=/etc --infodir=/usr/share/info --mandir=/usr/share/man --localstatedir=/var`.
  
  *make_cmd*::
      The executable to run at the `build` phase if `${build_style}` is set to
      `configure`, `gnu-configure` or `gnu-makefile` build methods.
      By default set to `make`.
  
  *make_build_args*::
      The arguments to be passed in to `${make_cmd}` at the build phase if
      `${build_style}` is set to `configure`, `gnu-configure` or `gnu_makefile`
      build methods. Unset by default.
  
  *make_install_args*::
      The arguments to be passed in to `${make_cmd}` at the `install-destdir`
      phase if `${build_style}` is set to `configure`, `gnu-configure` or
      `gnu_makefile` build methods. Unset by default.
  
  *make_build_target*::
      The target to be passed in to `${make_cmd}` at the build phase if
      `${build_style}` is set to `configure`, `gnu-configure` or `gnu_makefile`
      build methods. Unset by default (`all` target).
  
  *make_install_target*::
      The target to be passed in to `${make_cmd}` at the `install-destdir` phase
      if `${build_style}` is set to `configure`, `gnu-configure` or `gnu_makefile`
      build methods. By default set to `DESTDIR=${DESTDIR} install`.
  
  *patch_args*::
      The arguments to be passed in to the `patch(1)` command when applying
      patches to the package sources after `do_extract()`. Patches are stored in
      `srcpkgs/<pkgname>/patches` and must be in `-p0` format. By default set to `-Np0`.
  
  *disable_parallel_build*::
      If set the package won't be built in parallel and `XBPS_MAKEJOBS` has no effect.
  
  *keep_libtool_archives*::
      If enabled the `GNU Libtool` archives won't be removed. By default those
      files are always removed automatically.
  
  *skip_extraction*::
      A list of filenames that should not be extracted in the `extract` phase.
      This must match the basename of any url defined in `${distfiles}`.
      Example `skip_extraction="foo-${version}.tar.gz"`.
  
  *force_debug_pkgs*::
      If enabled binary packages with debugging symbols will be generated
      even if `XBPS_DEBUG_PKGS` is disabled in `xbps-src.conf` or in the
      `command line arguments`.
  
  build style scripts
  ~~~~~~~~~~~~~~~~~~~
  The `build_style` variable specifies the build method to build and install a
  package. It expects the name of any available script in the
  `/usr/share/xbps-src/build_style` directory. Please note that required packages
  