|GERMINATE(1)||General Commands Manual||GERMINATE(1)|
germinateis a program to help with the maintenance of large software distributions. It takes a list of seed packages and a mirror of the distribution, and produces outputs with the seed packages and their dependencies and build-dependencies expanded out in full.
Seeds¶The contents of the Ubuntu distribution, and others, are managed by means of seeds. At their simplest, these are lists of packages which are considered important to have in the main component of the distribution, without explicitly listing all their dependencies and build-dependencies.
Seed lists are typically divided up by category: a
minimal seed might
list the core set of packages required to make the system run at all, while
desktop seed might list the set of packages
installed as part of a default desktop installation.
germinate takes these seeds, adds their dependency
trees, and produces an output for each seed which contains
a dependency-expanded list of package names. These outputs may be handed on
to archive maintenance or CD-building tools.
Some seeds may inherit from other seeds: they
rely on those seeds to be installed. For example, a
desktop seed will typically inherit from a
understands these inheritance relationships. If a package in the
desktop seed depends on ‘foo’, but
‘foo’ is already part of the
seed or dependency list, then ‘foo’ will not be added to the
Seeds are stored in text files downloaded from a given URL. Lines not beginning with ‘ * ’ (wiki-style list markup) are ignored.
Seed entries may simply consist of a package name, or may include any of the following special syntax:
- Seed entries beginning with ‘%’ expand to all binaries from the given source package.
- Seed entries may be followed with ‘ [arch1 arch2 ...]’ to indicate that they should only be used on the given architectures, or with ‘ [!arch1 !arch2 ...]’ to indicate that they should not be used on the given architectures.
- Seed entries in parentheses indicate that the seed should be treated as a recommendation of metapackages generated from this seed, rather than as a dependency.
- Seed entries beginning with ‘!’ cause the given package to
be blacklisted from the given seed and any seeds from which it inherits;
this may be followed by ‘%’ as above to blacklist all
binaries from the given source package. Note that this may result in
uninstallable packages whose dependencies have been blacklisted, so use
this feature sparingly. The purpose of a blacklist is to make it obvious
when a package that is not supposed to be installed ends up in
germinate's output, so that package relationships can be fixed to stop that happening. It is not intended for the purpose of working around buggy package relationships, and attempts to do so will not work because
apthas no way to know about blacklist entries in seeds.
- Seed entries beginning with ‘snap:’ are
snap packages. These are different from
deb packages in that they do not have
(build-)dependencies, cannot be recommended, and do not end up in any
resulting metapackages. (If you try to recommend a snap package, it will
be ignored completely.) Snaps specified in seeds will be output in a
.snaps file named after the corresponding seed, as
software processing the output of
germinatewill typically need to treat snaps differently from debs.
germinatewill not check remotely to see if a given snap is available, therefore seeds are expected to explicitly list all architectures a snap is to be seeded on. ‘snap:’ entries can also be suffixed with "/classic" to indicate that the snaps need to be installed with classic confinement on end-user systems.
- key: value
- Some seeds also contain headers at the top of the file, in “key:
value” format. For the most part, these are not parsed by
germinateitself. The Ubuntu
taskselpackage uses keys beginning with ‘Task-’ to define fields of similar names in its .desc files. germinate-update-metapackage(1) uses some of these headers to reduce the need for fragile configuration; see its documentation for further details.
A STRUCTURE file alongside the seeds lists their inheritance relationships. It may also include lines beginning with ‘include’, causing other collections of seeds to be included as if they were part of the collection currently being germinated, or lines beginning with ‘feature’, which set flags for the processing of seeds. Features may also be set on a per-seed basis using lines beginning with ‘ * Feature:’ in the seed file.
The following flags are currently defined:
- Follow Build-Depends fields. This flag is only recognised in individual seed files, not in STRUCTURE.
- Follow Build-Depends fields for Architecture: all packages. This has no
- Treat Recommends fields as if they were Depends.
- Do not follow Build-Depends fields.
- Do not follow Build-Depends fields for Architecture: all packages, even though Build-Depends are followed for other packages.
- Do not treat Recommends fields as if they were Depends. This flag is only recognised in individual seed files, not in STRUCTURE.
Build-dependencies and ‘supported’¶There is typically no need for a default desktop installation to contain all the compilers and development libraries needed to build itself from source; if nothing else, it would consume much more space. Nevertheless, it is normally a requirement for the maintainers of a distribution to support all the packages necessary to build that distribution.
germinate therefore does not add all the
packages that result from following build-dependencies of seed packages and
of their dependencies (the “build-dependency tree”) to every
output, unless they are also in the seed or in the dependency list. Instead,
it adds them to the output for the last seed in the
STRUCTURE file, conventionally called
Like any other seed, the supported seed may contain its own list of packages. It is common to provide support for many software packages which are not in the default installation, such as debugging libraries, optimised kernels, alternative language support, and the like.
Outputs¶The output files are named after the seed to which they correspond. An additional output file is needed for supported, namely ‘supported+build-depends’, which contains the supported list and the build-depends lists of the other seeds all joined together. An ‘all’ output is produced to represent the entire archive.
Some other files are produced for occasional use by experts. See the README file for full details on these.
- Be more verbose when processing seeds.
- Fetch seeds from the specified sources. The default is
-vcs=bzr option is used, or git://git.launchpad.net/~ubuntu-core-dev/ubuntu-seeds/+git/ if the
-vcs=git option is used. You may use file:// URLs here to fetch seeds from the local file system; for example, if your seeds are stored in /home/username/seeds/debian.unstable, then you would use the options
- Fetch seeds for distribution dist. The default is
When fetching seeds from git, the part after the rightmost ‘.’ character, if any, is treated as the branch name to check out; this rather strange style is for backward compatibility.
- Get package lists from mirror. The default is http://archive.ubuntu.com/ubuntu/. May be supplied multiple times; the newest version of each package across all archives will win.
- Get source package lists from mirror. The default is to use package lists mirrors. May be supplied multiple times; the newest version of each source package across all archives will win.
- Operate on the specified distributions. The default is
bionic. Listing multiple distributions may be useful, for example, when examining both a released distribution and its security updates.
- Operate on architecture arch. The default is
- Operate on the specified components. The default is
- Check out seeds from a version control system rather than fetching them
directly from a URL. Requires
git, as appropriate, to be installed. For
bzr, use the branch found at seed-source/seed-dist; for
git, remove the part after the rightmost ‘.’ character of seed-dist and use it as the branch name to check out from seed-source/remainder-of-seed-dist. For
auto, guess the version control system to use from seed-source (trying both in ambiguous cases) and then proceed as above.
- Check out seeds from the
bzrbranch found at seed-source/seed-dist rather than fetching them directly from a URL. Requires
bzrto be installed. This option is deprecated and is retained for backward compatibility; use
- Disable reverse-dependency calculations. These calculations cause a large number of small files to be written out in the rdepends/ directory, and may take some time.
- Do not consider debian-installer udeb packages. While generally not the desired outcome, sometimes you might wish to omit consideration of installer packages when processing your seeds, perhaps if sending the output directly to the package manager on an already-installed system.
- Treat each pkg as a seed by itself, inheriting from
parent (i.e. assuming that all packages in the
parent seed are already installed while calculating
the additional dependencies of pkg). This allows the
germinateto calculate the dependencies of individual extra packages. For example,
-seed-packagesdesktop/epiphany-browser will create an epiphany-browser output file listing the additional packages that need to be installed over and above the desktop seed in order to install epiphany-browser.
- Always follow Build-Depends in all seeds, regardless of seed feature flags.
BUGS¶The wiki-style markup in seeds was inherited from an early implementation, and is a wart.
germinate can sometimes be confused by
complicated situations involving the order in which it encounters
dependencies on virtual packages. Explicit entries in seeds may be required
to work around this.
Handling of installer packages (udebs) is complicated, poorly documented, and doesn't always work quite right: in particular, packages aren't demoted to the supported seed when they should be.
AUTHORS¶Scott James Remnant ⟨email@example.com⟩
Colin Watson ⟨firstname.lastname@example.org⟩
germinate is copyright © 2004,
2005, 2006, 2007, 2008 Canonical Ltd. See the GNU
General Public License version 2 or later for copying conditions. A copy of
the GNU General Public License is available in
|May 27, 2005||Ubuntu|