GNOME package guidelines

From ArchWiki
Arch package guidelines

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The GNOME packages on Arch Linux follow a certain schema.

Source URL

GNOME packages normally follow two source URL scheme: a released tarball stored in GNOME's FTP server and a specific commit in the software's Git repository

Using released tarball

When downloading a released tarball, you can get it from https://download.gnome.org using the following source array: 

source=("https://download.gnome.org/sources/$pkgname/${pkgver%.*}/$pkgname-$pkgver.tar.xz")

where ${pkgver%.*} returns the major.minor package version, by removing the suffix of pkgver (which is the micro package version). E.g., if pkgver=3.28.0 then ${pkgver%.*} would return 3.28.

Using a commit from Git repository

Another common practice is to use as source a specific commit from a GNOME software's source code git repository. It does not classify as a VCS package because Pacman's feature of setting specific commit (see PKGBUILD(5) § USING VCS SOURCES) makes PKGBUILD not follow latest development commits neither update the pkgver field, using the source from the specified commit hash instead.

See a template below: 

PKGBUILD
url="https://gitlab.gnome.org/GNOME/$pkgname"
makedepends=(git)
_commit=hash_of_a_commit  # tags/X.Y.Z 
source=("git+${url}.git#commit=$_commit")
md5sums=('SKIP')

pkgver() {
  cd $pkgname
  git describe --tags | sed 's/-/+/g'
}

Replace hash_of_a_commit with the Git commit hash desired, and replace the pkgver() statement to fit the needs of the package you are packaging (see VCS package guidelines#Git).

Please notice that since the source is downloaded with git, then git must be in makedepends and checksums must be set to 'SKIP', just like it would happen with any other VCS package. Using pkgver() function is highly recommended, so it sets pkgver accordingly for the commit hash provided.

Note: GNOME previously used https://git.gnome.org, but then migrated to https://gitlab.gnome.org[1]. Old links should automatically redirect to the new gitlab.gnome.org domain, but it might be wise to manually update your source URL.

Meson and GNU build systems

Historically GNOME used GNU Build System to build its applications. While there some currently active applications and many inactive applications that still use GNU Build System, most of currently active GNOME applications migrated to Meson Build System.

See Meson package guidelines for instructions that fits the packaging needs of most GNOME applications.

Note: Even though GNOME applications are written in different programming languages, you should stick with Meson if that is the build system set for that GNOME application. E.g. Do not use Rust package guidelines for GNOME applications written in Rust language because you should use meson, not rustc or cargo to build it.

GSettings schemas

GSettings are the current schemas used by GNOME applications, and can be accessed/read/edited using the GUI tool dconf or the CLI tool gsettings (provided by glib2, which is most likely already installed as dependency). GSettings used to require some attention of the packager, but nowadays no intervention is required.

Some observations:

  • Applications that use GSettings normally depends on GTK (gtk3 or later), so GSettings-related dependencies are normally already satisfied.
  • --disable-schemas-compile flag in ./configure used to be required to avoid recompiling GSettings database on package() function, but this no longer applies to GNOME applications for some time now, mainly in applications using Meson as build system.
Warning: Even for old, non-Meson GNOME applications, do not call glib-compile-schemas in the .install file, as GSettings schema databases are automatically recompiled via pacman hooks since glib2=2.48.0-2.

GConf schemas

Most GNOME packages migrated from GConf schemas to #GSettings schemas, but you may cross with an old and obsolete GNOME package to installs these GConf schemas. In these cases, gconfAUR must be added to depends array.

Gconf schemas get installed in the system GConf database, which has to be avoided. Some packages provide a --disable-schemas-install flag for ./configure, which hardly ever works. However, gconftool-2 has a variable called GCONF_DISABLE_MAKEFILE_SCHEMA_INSTALL which you can set to tell gconftool-2 to not update any databases.

When creating packages that install GConf schema files, use 

make GCONF_DISABLE_MAKEFILE_SCHEMA_INSTALL=1 DESTDIR="${pkgdir}" install

in the PKGBUILD's package() function.

Warning: Do not call gconfpkg in the .install file, as GConf schemas are automatically installed/removed (while installing/removing the GNOME package) via pacman hooks since gconfAUR=3.2.6-4.

ScrollKeeper documentation

GNOME applications do not use ScrollKeeper nowadays, but you might come across with a GTK2-based application with that documentation.

Since GNOME 2.20 there is no need to run any command for ScrollKeeper, as rarianAUR reads its OMF files directly. scrollkeeper-update is a dummy these days. The only requirement is to include gnome-doc-utilsAUR to makedepends array.

You can disable documentation generation using --disable-scrollkeeper flag from ./configure.

GTK icon cache

Many graphical GNOME applications install icons in the system, and those icons are included in an icon cache via the gtk-update-icon-cache tool. Every time an icon is added or remove, this tool is used to update the cache.

Note:

.desktop files

Many packages install Freedesktop.org-compatible .desktop files and register MimeType entries in them. These information is stored in a database that has to be updated on every addition or removal. This is the function of the update-desktop-database tool.

Note:
  • Do not call update-desktop-database in the .install file, as the database is automatically updated via pacman hooks since desktop-file-utils=0.22-2.
  • The package does not need to depend on desktop-file-utils, as this dependency will be satisfied by packages like gtk4 etc.

AppStream and metainfo files

As many others, most GNOME applications adheres the Freedesktop.org's AppStream specification and provide a metainfo file so that a description of the application is shown in application centers, like gnome-software or Flathub.

GNOME applications usually validate metainfo files if appstream-util tool when meson test is called in check() function. If appstream-glib is not installed, this will simply prevent this particular validation from being executed (i.e. no error will interrupt the build process).

You can identify that appstream-util is used by the application using two methods:

  • The first method is to look in the source code for appstream-util by running grep -R appstream-util or looking at data/meson.build file;
  • The other method is to read the build process looking for 
    Program appstream-util found: NO

Add appstream-glib to checkdepends array to validate metainfo file.