Gentoo Development Guide
Keywording
Note
Terminology: The term 'package' refers to an entire directory, for example
app-editors/vim
—
it does not refer to a specific version. The terms
'ebuild' or 'package version' are used when this meaning is intended. This
distinction is important.
Every ebuild must specify a KEYWORDS variable. This variable is used to
indicate the suitability and stability of both the package and the ebuild on
each given arch (sparc, ppc, x86-obsd, ...).
Note
The term 'arch' is used in this sense for historical reasons. As a result of GLEP 22 and the various non-Linux ports, this is no longer a particularly accurate term.
A sample KEYWORDS entry might look like:
KEYWORDS="x86 sparc ~mips ~ppc ~ppc-macos -ia64"
The different levels of keyword are:
-
arch(x86,ppc-macos) - Both the package version and the ebuild are widely tested, known to work and not have any serious issues on the indicated platform.
-
~arch(~x86,~ppc-macos) -
The package version and the ebuild are believed to work and do not have any
known serious bugs, but more testing is required before the package version
is considered suitable for
arch. - No keyword
-
If a package has no keyword for a given arch, it means it is not known
whether the package will work, or that insufficient testing has occurred for
~arch. -
-arch(-x86,-ppc-macos) - The package version will not work on the arch. This could be caused by badly written code (for example, non-64-bit or endian clean code), relying upon particular hardware (for example, a BIOS querying tool would not work on non-BIOS architectures) or binary only packages.
The -* keyword is special. It is used to indicate package versions which are
not worth trying to test on unlisted archs. For example, a binary-only package
which is only supported upstream on x86 and ppc might use:
KEYWORDS="-* x86 ppc"
This is different in implication from "x86 ppc"
—
the former implies that
it will not work on other archs, whereas the latter implies that it has not been
tested.
Do not use the * or ~* special keywords in ebuilds.
Equal Visibility Requirement
An ebuild must not depend upon any package that is of a lower keyword level
than itself. For example, if foo-1.2 depends upon bar-1.2, and
bar-1.2 is ~x86, then foo-1.2 must not be marked stable on
x86 unless bar-1.2 is also stabilised.
You may assume that if a user accepts ~arch for a given arch then they also
accept arch.
For optional dependencies, all possible dependencies must satisfy the above.
Note that certain USE flags can be forcibly disabled on a per-profile basis
—
talk to the arch teams if you require this. For either-or dependencies, at
least one of the options must be of equal or better visibility than the
package in question.
Hard Masks
The package.mask file can be used to 'hard mask' individual or groups of
ebuilds. This should be used for testing ebuilds or beta releases of software,
and may also be used if a package has serious compatibility problems. Packages
which are not hard masked must not have a dependency upon hard masked
packages.
The only time it is acceptable for a user to see the Possibly a DEPEND
problem error message is if they have manually changed visibility levels for a
package (for example, through /etc/portage/) and have missed a dependency.
You should never commit a change which could cause this error to appear on a
user system.
Keywording New Packages
Important
New packages should be marked as ~arch only upon
architectures for which the committing developer has tested.
Do not assume that your package works on all architectures. Do not
assume that user submitted ebuilds will have correct KEYWORDS
—
chances are
they just copied from somewhere else. Do not assume that upstream's
'supported architectures' list is correct. Do not assume that because your
code is written in Perl / Python / Java / whatever that it will run on other
archs (there is at least one case of a vim script which only worked on
x86).
Note that most (non-x86) archs expect you to be on the arch team and bugzilla
alias if you are committing packages with keywords for that arch, and may have
additional requirements of which you should be aware (on mips, for example,
there are multiple ABIs and byte orders to consider
—
a package working on your
o32 box may not work on o64 or n32). Contact the individual arch
teams for details.
It's important to note that alternative arches (like alpha, ia64, s390, sh, sparc, hppa, ppc*) are mainly undermanned arches, some of them are slow, they have more basic problems and have a small userbase. Just file bugs for these architectures when a package is going to be a dependency of a package already keyworded.
Do not commit straight to arch.
Keywording on Upgrades
When upgrading, drop all existing keywords from arch to ~arch, and leave
any existing ~arch keywords intact. This must be done even if you think
you're just making a trivial fix
—
there have been several examples of the
stable tree getting broken this way.
Sometimes you may need to remove a keyword because of new unresolved dependencies. If you do this, you must file a bug notifying the relevant arch teams.
This also applies to revision bumps, not just to upstream version changes.
Moving from ~arch to arch
Moving a package from ~arch to arch is done only by the relevant arch teams.
If you have access to non-x86 hardware but are not on the arch teams, you may wish
to make individual arrangements
—
the arch teams are happy for help, so long as
they know what is going on. Please note that x86 is now no longer an exception
and stabilisation must be done through the x86 arch team unless you have
individual arrangements
—
see
GLEP 40
for further details.
For a package to move to stable, the following guidelines must be met:
-
The package has spent a reasonable amount of time in
~archfirst. Thirty days is the usual figure, although this is clearly only a guideline. For critical packages, a much longer duration is expected. For small packages which have only minor changes between versions, a shorter period is sometimes appropriate. -
The package must not have any non-
archdependencies. - The package must not have any severe outstanding bugs or issues.
- The package must be widely tested.
- If the package is a library, it should be known not to break any package which depends upon it.
For security fixes, the "reasonable amount of time" guideline may be relaxed. See the Vulnerability Treatment Policy
Removing Package Versions
When removing ebuild, ensure that you do not remove the most recent version at any given keyword level on any profile. The aim here is:
-
Never to force a downgrade. (Exception: occasionally you really do want to
force a downgrade, for example if the newly committed
foo-1.3turns out to be badly broken and that making everyone downgrade tofoo-1.2is the better option. This is rare.) - Do not break any existing dependencies.
If you would like a particular package version moved to stable on certain archs so that you can tidy up, file a bug.