commit: 0719b0f628b12a542b4e9b3327ab493c0e1daf76 Author: Michał Górny <mgorny <AT> gentoo <DOT> org> AuthorDate: Sun Jan 19 20:29:58 2020 +0000 Commit: Michał Górny <mgorny <AT> gentoo <DOT> org> CommitDate: Tue Jan 21 16:47:48 2020 +0000 URL: https://gitweb.gentoo.org/proj/policy-guide.git/commit/?id=0719b0f6
dependencies: policy on 4-style USE deps Closes: https://bugs.gentoo.org/705890 Closes: https://github.com/gentoo/policy-guide/pull/8 Signed-off-by: Michał Górny <mgorny <AT> gentoo.org> dependencies.rst | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/dependencies.rst b/dependencies.rst index 38f4147..55bba5c 100644 --- a/dependencies.rst +++ b/dependencies.rst @@ -167,5 +167,46 @@ dependencies as a result. if the package installed by the user still links to libfoo. +.. index:: + pair: USE flags; dependency + +USE dependencies +---------------- + +on packages without the flag +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +:Source: QA (inferred from PMS) +:Reported: by pkgcheck + +Whenever a package uses a 2-style USE-dependency on another package, +all package versions matching the dependency must have the flag +in question. If the dependency matches at least one version missing +the flag, either 4-style USE-dependency (i.e. having ``(-)`` or ``(+)`` +indicator) must be used, or the restriction must be refined to match +only versions having the flag. + +*Example*:: + + # BAD: USE=gtk2 is not supported by v2 + dev-foo/libfrobnicate[gtk2] + # GOOD: all matching versions have USE=tools + <dev-foo/libfrobnicate-2[gtk2] + # GOOD: indicate the default + dev-foo/libfrobnicate[gtk2(-)] + + # BAD: USE=tools is no longer needed with v2 + dev-foo/libbar[tools] + # GOOD: indicate the default + dev-foo/libbar[tools(+)] + +*Rationale*: according to the PMS section on `2-style and 4-style USE +dependencies`_, it is an error to apply 2-style USE dependency to +a package missing the flag. Furthermore, checking for this makes it +possible to report whenever USE flags on a package are changed without +updating its reverse dependencies. + + .. _GLEP 62: https://www.gentoo.org/glep/glep-0062.html .. _Paludis: https://paludis.exherbo.org/ +.. _2-style and 4-style USE dependencies: + https://projects.gentoo.org/pms/7/pms.html#x1-790008.2.6.4
