Difference between revisions of "Creating packages"
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=== Meta packages and groups ===
=== Meta packages and groups ===
A package group is a set of related packages, defined by the packager, which can be installed or uninstalled simultaneously by using the group name as a substitute for each individual package name.
A package group is a set of related packages, defined by the packager, which can be installed or uninstalled simultaneously by using the group name as a substitute for each individual package name. a group is not a package, it can be installed in a similar fashion to a package see [[Pacman#Installing package groups]] and [[PKGBUILD#groups]].
A meta package, often (though not always) titled with the ''-meta'' suffix, provides similar functionality to a package group in that it enables multiple related packages to be installed or uninstalled simultaneously. Meta packages can be installed just like any other package
A meta package, often (though not always) titled with the ''-meta'' suffix, provides similar functionality to a package group in that it enables multiple related packages to be installed or uninstalled simultaneously. Meta packages can be installed just like any other package see [[Pacman#Installing specific packages]]. The only difference between a meta package and a regular package is that a meta package is empty and exists purely to link related packages together via dependencies.
The advantage of a meta package, compared to a group, is that any new member packages will be installed when the meta package itself is updated with a new set of dependencies. This is in contrast to a group where new group members will not be automatically installed. The disadvantage of a meta package is that it is not as flexible as a group
The advantage of a meta package, compared to a group, is that any new member packages will be installed when the meta package itself is updated with a new set of dependencies. This is in contrast to a group where new group members will not be automatically installed. The disadvantage of a meta package is that it is not as flexible as a groupyou can choose which group members you wish to install but you cannot choose which meta package dependencies you wish to install. Likewiseyou can uninstall group members without having to remove the entire groupyou cannot remove meta package dependencies without having to uninstall the meta package itself.
== Preparation ==
== Preparation ==
Latest revision as of 19:13, 5 October 2017
This article aims to assist users creating their own packages using the Arch Linux "ports-like" build system, also for submission in AUR. It covers creation of a PKGBUILD – a package build description file sourced by
makepkg to create a binary package from source. If already in possession of a
PKGBUILD, see makepkg. For instructions regarding existing rules and ways to improve package quality see Arch packaging standards.
- 1 Overview
- 2 Preparation
- 3 Creating a PKGBUILD
- 4 Testing the PKGBUILD and package
- 5 Submitting packages to the AUR
- 6 Summary
- 7 More detailed guidelines
- 8 PKGBUILD generators
- 9 See also
Packages in Arch Linux are built using the makepkg utility and the information stored in a PKGBUILD file. When
makepkg runs, it searches for a
PKGBUILD in the current directory and follows the instructions in it to acquire the required files and/or compile them to be packed within a package file (
pkgname.pkg.tar.xz). The resulting package contains binary files and installation instructions ready to be installed by pacman.
An Arch package is no more than a tar archive, or 'tarball', compressed using xz, which contains the following files generated by makepkg:
- The binary files to install.
.PKGINFO: contains all the metadata needed by pacman to deal with packages, dependencies, etc.
.MTREE: contains hashes and timestamps of the files, which are included in the local database so that pacman can verify the integrity of the package.
.INSTALL: an optional file used to execute commands after the install/upgrade/remove stage. (This file is present only if specified in the
.Changelog: an optional file kept by the package maintainer documenting the changes of the package. (It is not present in all packages.)
Meta packages and groups
A package group is a set of related packages, defined by the packager, which can be installed or uninstalled simultaneously by using the group name as a substitute for each individual package name. While a group is not a package, it can be installed in a similar fashion to a package (see Pacman#Installing package groups and PKGBUILD#groups).
A meta package, often (though not always) titled with the -meta suffix, provides similar functionality to a package group in that it enables multiple related packages to be installed or uninstalled simultaneously. Meta packages can be installed just like any other package (see Pacman#Installing specific packages). The only difference between a meta package and a regular package is that a meta package is empty and exists purely to link related packages together via dependencies.
The advantage of a meta package, compared to a group, is that any new member packages will be installed when the meta package itself is updated with a new set of dependencies. This is in contrast to a group where new group members will not be automatically installed. The disadvantage of a meta package is that it is not as flexible as a group; you can choose which group members you wish to install but you cannot choose which meta package dependencies you wish to install. Likewise, you can uninstall group members without having to remove the entire group. However, you cannot remove meta package dependencies without having to uninstall the meta package itself.
First ensure that the necessary tools are installed. Installing the package group should be sufficient; it includes make and additional tools needed for compiling from source.
One of the key tools for building packages is makepkg (provided by ), which does the following:
- Checks if package dependencies are installed.
- Downloads the source file(s) from the specified server(s).
- Unpacks the source file(s).
- Compiles the software and installs it under a fakeroot environment.
- Strips symbols from binaries and libraries.
- Generates the package meta file which is included with each package.
- Compresses the fakeroot environment into a package file.
- Stores the package file in the configured destination directory, which is the present working directory by default.
Download and test the installation
Download the source tarball of the software you want to package, extract it, and follow the author's steps to install the program. Make a note of all commands and/or steps needed to compile and install it. You will be repeating those same commands in the PKGBUILD file.
Most software authors stick to the 3-step build cycle:
./configure make make install
This is a good time to make sure the program is working correctly.
Creating a PKGBUILD
When you run
makepkg, it will look for a
PKGBUILD file in the present working directory. If a
PKGBUILD file is found it will download the software's source code and compile it according to the instructions specified in the
PKGBUILD file. The instructions must be fully interpretable by the Bash shell. After successful completion, the resulting binaries and metadata of the package, i.e. package version and dependencies, are packed in a
pkgname.pkg.tar.xz package file that can be installed with
pacman -U <package file>.
To begin with a new package, you should first create an empty working directory, change into that directory, and create a
PKGBUILD file. You can either copy the prototype PKGBUILD from the
/usr/share/pacman/ directory to your working directory or copy a
PKGBUILD from a similar package. The latter may be useful if you only need to change a few options.
Defining PKGBUILD variables
Example PKGBUILDs are located in
/usr/share/pacman/. An explanation of possible
PKGBUILD variables can be found in the PKGBUILD article.
makepkg defines two variables that you should use as part of the build and install process:
- This points to the directory where makepkg extracts or symlinks all files in the source array.
- This points to the directory where makepkg bundles the installed package, which becomes the root directory of your built package.
All of them contain absolute paths, which means, you do not have to worry about your working directory if you use these variables properly.
There are five functions, listed here in the order they are executed if all of them exist. If one does not exist, it is simply skipped.
This function, commands that are used to prepare sources for building are run, such as patching. This function runs right after package extraction, before pkgver() and the build function. If extraction is skipped (
makepkg -e), then
prepare() is not run.
pkgver() runs after the sources are fetched, extracted and prepare() executed. So you can update the pkgver variable during a makepkg stage.
This is particularly useful if you are making git/svn/hg/etc. packages, where the build process may remain the same, but the source could be updated every day, even every hour. The old way of doing this was to put the date into the pkgver field which, if the software was not updated, makepkg would still rebuild it thinking the version had changed. Some useful commands for this are
hg identify -ni, etc. Please test these before submitting a PKGBUILD, as a failure in the
pkgver() function can stop a build in its tracks.
Now you need to implement the
build() function in the
PKGBUILD file. This function uses common shell commands in Bash syntax to automatically compile software and create a
pkg directory to install the software to. This allows makepkg to package files without having to sift through your file system.
The first step in the
build() function is to change into the directory created by uncompressing the source tarball. makepkg will change the current directory to
$srcdir before executing the
build() function. Therefore, in most cases, like suggested in
/usr/share/pacman/PKGBUILD.proto, the first command will look like this:
Now, you need to list the same commands you used when you manually compiled the software. The
build() function in essence automates everything you did by hand and compiles the software in the fakeroot build environment. If the software you are packaging uses a configure script, it is good practice to use
--prefix=/usr when building packages for pacman. A lot of software installs files relative to the
/usr/local directory, which should only be done if you are manually building from source. All Arch Linux packages should use the
/usr directory. As seen in the
/usr/share/pacman/PKGBUILD.proto file, the next two lines often look like this:
./configure --prefix=/usr make
Place for calls to
make check and similar testing routines. It is highly recommended to have
check() as it helps to make sure software has been built correctly and works fine with its dependencies.
Users who do not need it (and occasionally maintainers who can not fix a package for this to pass) can disable it using
BUILDENV+=('!check') in PKGBUILD/makepkg.conf or call
The final step is to put the compiled files in a directory where makepkg can retrieve them to create a package. This by default is the
pkg directory—a simple fakeroot environment. The
pkg directory replicates the hierarchy of the root file system of the software's installation paths. If you have to manually place files under the root of your filesystem, you should install them in the
pkg directory under the same directory structure. For example, if you want to install a file to
/usr/bin, it should instead be placed under
$pkgdir/usr/bin. Very few install procedures require the user to copy dozens of files manually. Instead, for most software, calling
make install will do so. The final line should look like the following in order to correctly install the software in the
make DESTDIR="$pkgdir/" install
makepkg --repackage runs only the
package() function, so it creates a package without building. This may save time e.g. if you have changed just the
depends variable of the package.
Testing the PKGBUILD and package
As you are writing the
build() function, you will want to test your changes frequently to ensure there are no bugs. You can do this using the
makepkg command in the directory containing the
PKGBUILD file. With a properly formatted
PKGBUILD, makepkg will create a package; with a broken or unfinished
PKGBUILD, it will raise an error.
If makepkg finishes successfully, it will place a file named
pkgname-pkgver.pkg.tar.xz in your working directory. This package can be installed with the
pacman -U command. However, just because a package file was built does not imply that it is fully functional. It might conceivably contain only the directory and no files whatsoever if, for example, a prefix was specified improperly. You can use pacman's query functions to display a list of files contained in the package and the dependencies it requires with
pacman -Qlp [package file] and
pacman -Qip [package file] respectively.
If the package looks sane, then you are done! However, if you plan on releasing the
PKGBUILD file, it is imperative that you check and double-check the contents of the
Also ensure that the package binaries actually run flawlessly! It is annoying to release a package that contains all necessary files, but crashes because of some obscure configuration option that does not quite work well with the rest of the system. If you are only going to compile packages for your own system, though, you do not need to worry too much about this quality assurance step, as you are the only person suffering from mistakes, after all.
Checking package sanity
After testing package functionality check it for errors using namcap:
$ namcap PKGBUILD $ namcap <package file name>.pkg.tar.xz
- Check PKGBUILD contents for common errors and package file hierarchy for unnecessary/misplaced files
- Scan all ELF files in package using
ldd, automatically reporting which packages with required shared libraries are missing from
dependsand which can be omitted as transitive dependencies
- Heuristically search for missing and redundant dependencies
and much more. Get into the habit of checking your packages with namcap to avoid having to fix the simplest mistakes after package submission.
Submitting packages to the AUR
Please read AUR User Guidelines#Submitting packages for a detailed description of the submission process.
- Download the source tarball of the software you want to package.
- Try compiling the package and installing it into an arbitrary directory.
- Copy over the prototype
/usr/share/pacman/PKGBUILD.protoand rename it to
PKGBUILDin a temporary working directory.
- Edit the
PKGBUILDaccording to the needs of your package.
makepkgand see whether the resulting package is built correctly.
- If not, repeat the last two steps.
- Before you can automate the package building process, you should have done it manually at least once unless you know exactly what you are doing in advance, in which case you would not be reading this in the first place. Unfortunately, although a good bunch of program authors stick to the 3-step build cycle of "
make install", this is not always the case, and things can get real ugly if you have to apply patches to make everything work at all. Rule of thumb: If you cannot get the program to compile from the source tarball, and make it install itself to a defined, temporary subdirectory, you do not even need to try packaging it. There is not any magic pixie dust in
makepkgthat makes source problems go away.
- In a few cases, the packages are not even available as source and you have to use something like
sh installer.runto get it to work. You will have to do quite a bit of research (read READMEs, INSTALL instructions, man pages, perhaps ebuilds from Gentoo or other package installers, possibly even the MAKEFILEs or source code) to get it working. In some really bad cases, you have to edit the source files to get it to work at all. However,
makepkgneeds to be completely autonomous, with no user input. Therefore if you need to edit the makefiles, you may have to bundle a custom patch with the
PKGBUILDand install it from inside the
prepare()function, or you might have to issue some
sedcommands from inside the
More detailed guidelines
PKGBUILDs for some packages can be generated automatically.