# PKGBUILD

Related articles

- Arch packaging standards
- Arch Build System
- Creating packages
- Category:Package development
- pacman tips
- PKGBUILD Templates
- Arch User Repository
- makepkg
- pacman

A PKGBUILD is an Arch Linux package build description file (actually it is a shell script) used when creating packages.

Packages in Arch Linux are built using the makepkg utility and information stored in PKGBUILDs. When makepkg is run, it searches for a `PKGBUILD` in the current directory and follows the instructions therein to either compile or otherwise acquire the files to build a package file (`pkgname.pkg.tar.xz`). The resulting package contains binary files and installation instructions, readily installed with pacman.

This article discusses the variables used in PKGBUILDs. For information on the PKGBUILD functions, refer to Creating packages#PKGBUILD_Functions.

## Variables

The following are variables that can be filled out in the PKGBUILD file. `pkgname`, `pkgver`, `pkgrel`, and `arch` are all mandatory. `license` is not strictly necessary to build a package, but it is recommended for any PKGBUILDs you might want to share with others. `makepkg` produces warnings if it isn't present.

It is common practice to define the variables in the PKGBUILD in same order as given here. However, this is not mandatory, as long as correct Bash syntax is used.

### pkgname

The name of the package. It should consist of alphanumeric and any of the following characters @ . _ + - (at symbol, dot, underscore, plus, hyphen). All letters should be lowercase and names are not allowed to start with hyphens. For the sake of consistency, `pkgname` should match the name of the source tarball of the software you are packaging. For instance, if the software is in `foobar-2.5.tar.gz`, the `pkgname` value should be `foobar`. The present working directory the PKGBUILD file is in should also match the `pkgname`.

### pkgver

The version of the package. The value should be the same as the version released by the author of the package. It can contain letters, numbers, periods and underscore but CANNOT contain a hyphen. If the author of the package uses a hyphen in their version numbering scheme, replace it with an underscore. For instance, if the version is 0.99-10, it should be changed to 0.99_10. If the `pkgver` variable is used later in the PKGBUILD then the underscore can easily be substituted for a dash on usage e.g.:

    source=("$pkgname-${pkgver//_/-}.tar.gz")

### pkgrel

The release number of the package specific to Arch Linux. This value allows users to differentiate between consecutive builds of the same version of a package. When a new package version is first released, the release number starts at 1. As fixes and optimizations are made to the `PKGBUILD` file, the package will be re-released and the release number will increment by 1. When a new version of the package comes out, the release number resets to 1.

### pkgdir

This variable reflects the root directory of what will be put into the package. It is commonly used in `make DESTDIR="$pkgdir" install`.

### epoch

Used to force the package to be seen as newer than any previous versions with a lower epoch, even if the version number would normally not trigger such an upgrade. This value is required to be a positive integer; the default value if left unspecified is 0. This is useful when the version numbering scheme of a package changes (or is alphanumeric), breaking normal version comparison logic. See pacman(8) for more information on version comparisons.

Warning: Do not use epoch unless fully aware of the implications of doing so.

### pkgbase

An optional global directive is available when building a split package, pkgbase is used to refer to the group of packages in the output of makepkg and in the naming of source-only tarballs. If not specified, the first element in the pkgname array is used. All options and directives for the split packages default to the global values given in the PKGBUILD. Nevertheless, the following ones can be overridden within each split package's packaging function: pkgver, pkgrel, epoch, pkgdesc, arch, url, license, groups, depends, optdepends, provides, conflicts, replaces, backup, options, install and changelog. The variable is not allowed to begin with a hyphen.

### pkgdesc

The description of the package. The description should be about 80 characters or less and should not include the package name in a self-referencing way. For instance, "Nedit is a text editor for X11" should be written as "A text editor for X11."

Note: Do not follow this rule thoughtlessly when submitting packages to AUR. If package name differs from application name for some reason, inclusion of full name into description can be the only way to ensure that package can be found during search.

### arch

An array of architectures that the `PKGBUILD` file is known to build and work on. Currently, it should contain `i686` and/or `x86_64`, `arch=('i686' 'x86_64')`. The value `any` can also be used for architecture-independent packages.

You can access the target architecture with the variable `$CARCH` during a build, and even when defining variables. See also FS#16352. Example:

    depends=('foobar')
    if test "$CARCH" == x86_64; then
      depends+=('lib32-glibc')
    fi

### url

The URL of the official site of the software being packaged.

### license

The license under which the software is distributed. A licenses package has been created in `[core]` that stores common licenses in `/usr/share/licenses/common`, e.g. `/usr/share/licenses/common/GPL`. If a package is licensed under one of these licenses, the value should be set to the directory name, e.g. `license=('GPL')`. If the appropriate license is not included in the official licenses package, several things must be done:

1. The license file(s) should be included in: `/usr/share/licenses/pkgname/`, e.g. `/usr/share/licenses/foobar/LICENSE`.
2. If the source tarball does NOT contain the license details and the license is only displayed elsewhere, e.g. a website, then you need to copy the license to a file and include it.
3. Add `custom` to the `license` array. Optionally, you can replace `custom` with `custom:name of license`. Once a license is used in two or more packages in an official repository (including `[community]`), it becomes a part of the licenses package.

- The BSD, MIT, zlib/png and Python licenses are special cases and could not be included in the licenses package. For the sake of the `license` array, it is treated as a common license (`license=('BSD')`, `license=('MIT')`, `license=('ZLIB')` and `license=('Python')`) but technically each one is a custom license because each one has its own copyright line. Any packages licensed under these four should have its own unique license stored in `/usr/share/licenses/pkgname`. Some packages may not be covered by a single license. In these cases, multiple entries may be made in the license array, e.g. `license=('GPL' 'custom:name of license')`.
- Additionally, the (L)GPL has many versions and permutations of those versions. For (L)GPL software, the convention is:
  - (L)GPL - (L)GPLv2 or any later version
  - (L)GPL2 - (L)GPL2 only
  - (L)GPL3 - (L)GPL3 or any later version
- If after researching the issue no license can be determined, `PKGBUILD.proto` suggests using `unknown`. However, upstream should be contacted about the conditions under which the software is (and is not) available.

Tip: Some software authors do not provide separate license file and describe distribution rules in section of common ReadMe.txt. This information can be extracted in separate file during `build` phase with something like this: `sed -n '/This software/,/ thereof./p' ReadMe.txt > LICENSE`.

### groups

The group the package belongs in. For instance, when you install the kdebase package, it installs all packages that belong in the kde group.

### depends

An array of package names that must be installed before this software can be run. Version restrictions can be specified with comparison operators, e.g. `depends=('foobar>=1.8.0')`; if multiple restrictions are needed, the dependency can be repeated for each of them [1], e.g. `depends=('foobar>=1.8.0' 'foobar<2.0.0')`.

It is not necessary to specify the version of the packages required. You do not need to list packages that your software depends on if other packages your software depends on already have those packages listed in their dependency. For instance, gtk2 depends on glib2 and glibc. However, glibc does not need to be listed as a dependency for gtk2 because it is a dependency for glib2.

Warning: The group base-devel is assumed to be already installed when building with makepkg. Members of "base-devel" should not be included in `depends` arrays.

### optdepends

An array of package names that are not needed for the software to function but provides additional features. A short description of the extra functionality each optdepend provides for the package should also be noted. An `optdepends` may look like this:

    optdepends=(
      'cups: printing support'
      'sane: scanners support'
      'libgphoto2: digital cameras support'
      'alsa-lib: sound support'
      'giflib: GIF images support'
      'libjpeg: JPEG images support'
      'libpng: PNG images support'
    )

Warning: The group base-devel is assumed to be already installed when building with makepkg. Members of "base-devel" should not be included in `optdepends` arrays.

### makedepends

An array of package names that must be installed to build the software but unnecessary for using the software after installation. You can specify the minimum version dependency of the packages in the same format as the `depends` array.

Note: Specifying packages that are already in `depends` is not necessary.
Warning: The group base-devel is assumed to be already installed when building with makepkg. Members of "base-devel" should not be included in `makedepends` arrays.

### checkdepends

An array of packages this package depends on to run its test suite but are not needed at runtime. Packages in this list follow the same format as depends. These dependencies are only considered when the check() function is present and is to be run by makepkg.

Warning: The group base-devel is assumed to be already installed when building with makepkg. Members of "base-devel" should not be included in `checkdepends` arrays.

### provides

An array of package names that this package provides the features of (or a virtual package such as `cron` or `sh`). Packages that provide the same things can be installed at the same time unless conflict with each other (see below). If you use this variable, you should add the version (`pkgver` and perhaps the `pkgrel`) that this package will provide if dependencies may be affected by it. For instance, if you are providing a modified qt package named qt-foobar version 3.3.8 which provides qt then the `provides` array should look like `provides=('qt=3.3.8')`. Putting `provides=('qt')` will cause to fail those dependencies that require a specific version of qt. Do not add `pkgname` to your provides array; this is done automatically.

### conflicts

An array of package names that may cause problems with this package if installed. A package with this name and all packages which `provides` virtual packages with this name will be removed. You can also specify the version properties of the conflicting packages in the same format as the `depends` array.

### replaces

An array of obsolete package names that are replaced by this package, e.g. `replaces=('wireshark')` for the wireshark-gtk package. After syncing with `pacman -Sy`, it will immediately replace an installed package upon encountering another package with the matching `replaces` in the repositories. If you are providing an alternate version of an already existing package, use the `conflicts` variable which is only evaluated when actually installing the conflicting package.

### backup

An array of files that can contain user-made changes and should be preserved during upgrade or removal of a package, primarily intended for configuration files in `/etc`.

When updating, new version may be saved as `file.pacnew` to avoid overwriting a file which already exists and was previously modified by the user. Similarly, when the package is removed, user-modified file will be preserved as `file.pacsave` unless the package was removed with `pacman -Rn` command.

The file paths in this array should be relative paths (e.g. `etc/pacman.conf`) not absolute paths (e.g. `/etc/pacman.conf`). See also Pacnew and Pacsave files.

### options

This array allows you to override some of the default behavior of `makepkg`, defined in `/etc/makepkg.conf`. To set an option, include the option name in the array. To reverse the default behavior, place an `!` at the front of the option.

The full list of the available options can be found in `man PKGBUILD`.

### install

The name of the `.install` script to be included in the package. pacman has the ability to store and execute a package-specific script when it installs, removes or upgrades a package. The script contains the following functions which run at different times:

- pre_install - The script is run right before files are extracted. One argument is passed: new package version.
- post_install - The script is run right after files are extracted. One argument is passed: new package version.
- pre_upgrade - The script is run right before files are extracted. Two arguments are passed in the following order: new package version, old package version.
- post_upgrade - The script is run right after files are extracted. Two arguments are passed in the following order: new package version, old package version.
- pre_remove - The script is run right before files are removed. One argument is passed: old package version.
- post_remove - The script is run right after files are removed. One argument is passed: old package version.

Each function is run chrooted inside the pacman install directory. See this thread.

Tip: A prototype `.install` is provided at `/usr/share/pacman/proto.install`. For a web-based prototype, refer to pacman's gitweb page.

### changelog

The name of the package changelog. To view changelogs for installed packages (that have this file):

    pacman -Qc pkgname

Tip: A prototype changelog file is provided at `/usr/share/pacman/ChangeLog.proto`.

### source

An array of files which are needed to build the package. It must contain the location of the software source, which in most cases is a full HTTP or FTP URL. The previously set variables `pkgname` and `pkgver` can be used effectively here (e.g. `source=("https://example.com/$pkgname-$pkgver.tar.gz")`).

Note: If you need to supply files which are not downloadable on the fly, e.g. self-made patches, you simply put those into the same directory where your `PKGBUILD` file is in and add the file name to this array. Any paths you add here are resolved relative to the directory where the `PKGBUILD` lies. Before the actual build process is started, all of the files referenced in this array will be downloaded or checked for existence, and `makepkg` will not proceed if any are missing.
Tip: You can specify a different name for the downloaded file — if the downloaded file has a different name for some reason, like the URL had a GET parameter — using the following syntax: `filename::fileuri`

For example:

    source=("project_name::hg+https://googlefontdirectory.googlecode.com/hg/")

### noextract

An array of files listed under the `source` array which should not be extracted from their archive format by `makepkg`. This most commonly applies to archives which cannot be handled by `/usr/bin/bsdtar` because libarchive processes all files as streams rather than random access as unzip does. In these situations, the alternative unarchiving tool (e.g., `unzip`, `p7zip`, etc.) should be added in the `makedepends` array and the first line of the prepare() function should extract the source archive manually; for example:

    unzip [source].zip

Note that while the `source` array accepts URLs, `noextract` is just the file name portion. So, for example, you would do something like this (simplified from grub2's PKGBUILD):

    source=("http://ftp.archlinux.org/other/grub2/grub2_extras_lua_r20.tar.xz")
    noextract=('grub2_extras_lua_r20.tar.xz')

To extract nothing, you can do something fancy like this (taken from firefox-i18n):

    noextract=("${source[@]%%::*}")

Note: More conservative Bash substitution would possibly include a loop that calls `basename`. If you have read this far, you should get the idea.

### md5sums

An array of MD5 checksums of the files listed in the `source` array. Once all files in the `source` array are available, an MD5 hash of each file will be automatically generated and compared with the values of this array in the same order they appear in the `source` array. While the order of the source files itself does not matter, it is important that it matches the order of this array because `makepkg` cannot guess which checksum belongs to what source file. You can generate this array quickly and easily using the command `updpkgsums` in the directory that contains the `PKGBUILD` file.

Note: The MD5 algorithm is known to have weaknesses; you should consider using a stronger alternative from the SHA-2 family of hash algorithms, such as SHA-256.

### sha1sums

An array of 160-bit SHA-1 checksums. This is an alternative to `md5sums` described above. To enable use and generation of these checksums, set up the `INTEGRITY_CHECK` option in `/etc/makepkg.conf`. See `man makepkg.conf`.

Note: The SHA-1 algorithm is known to have weaknesses; you should consider using a stronger alternative from the SHA-2 family of hash algorithms, such as SHA-256.

### sha256sums, sha384sums, sha512sums

An array of SHA-2 checksums with digest sizes 256, 384, and 512 bits, respectively. These are alternatives to `md5sums` and `sha1sums` described above and have fewer known weaknesses. To enable use and generation of these checksums, set up the `INTEGRITY_CHECK` option in `/etc/makepkg.conf`. See `man makepkg.conf`.

## See also

- PKGBUILD(5) Manual Page
- Example PKGBUILD file

Category:

- Package development