Sending this to dev ML in advance given it's simple and "probably" won't need to change the code further.
If interested in the whole deal, see the PR instead: https://github.com/gentoo/gentoo/pull/40942 --- (actual commit message below) Both the slotting method and eclass are meant to be as simple as possible, and isolated so that it does not really need to work with everything given non-slotted ffmpeg stays. Did not want turn ffmpeg into a permanent slotting model with a FFMPEG_SLOT use_expand, eselect, or such potentially turning it into a special Gentoo-only thing that often need hacks. Essentially just a way for broken packages to gain time without blocking everyone's ffmpeg updates. Signed-off-by: Ionen Wolkens <io...@gentoo.org> --- eclass/ffmpeg-compat.eclass | 69 +++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 eclass/ffmpeg-compat.eclass diff --git a/eclass/ffmpeg-compat.eclass b/eclass/ffmpeg-compat.eclass new file mode 100644 index 000000000000..2d675ab4cc66 --- /dev/null +++ b/eclass/ffmpeg-compat.eclass @@ -0,0 +1,69 @@ +# Copyright 2025 Gentoo Authors +# Distributed under the terms of the GNU General Public License v2 + +# @ECLASS: ffmpeg-compat.eclass +# @MAINTAINER: +# Ionen Wolkens <io...@gentoo.org> +# @AUTHOR: +# Ionen Wolkens <io...@gentoo.org> +# @SUPPORTED_EAPIS: 8 +# @BLURB: Helper functions to link with slotted ffmpeg-compat libraries +# @DESCRIPTION: +# To use this, run ``ffmpeg_compat_setup <slot>`` before packages use +# pkg-config, depend on media-video/ffmpeg-compat:<slot>=, and ensure +# usage of both pkg-config --cflags and --libs (which adds -Wl,-rpath +# to find libraries at runtime). +# +# This eclass is intended as a quick-to-setup alternative to setting +# an upper bound on ffmpeg for packages broken with the latest version, +# and thus allow users to upgrade their normal ffmpeg. +# +# This should still be a temporary measure, and it is recommended to +# keep migration bugs open rather than consider this eclass as being +# the "fix". +# +# Unlike LLVM_SLOT-style, this does not have USE to select the slot +# and should instead pick only the highest one usable until package +# is fixed and can use non-slotted ffmpeg again. +# +# Do *not* use both like ``|| ( <ffmpeg-<ver> ffmpeg-compat:<slot> )``, +# the package manager cannot know which version it linked against +# without USE flags. Unfortunately means a period where users may +# have two identical versions in stable before the newest major version +# is stabilized, but idea is to not mangle normal ffmpeg with slotting +# logic and make this an isolated temporary deal. + +case ${EAPI} in + 8) ;; + *) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;; +esac + +if [[ -z ${_FFMPEG_COMPAT_ECLASS} ]]; then +_FFMPEG_COMPAT_ECLASS=1 + +# @FUNCTION: ffmpeg_compat_get_prefix +# @USAGE: <slot> +# @DESCRIPTION: +# Return prefix of the installed ffmpeg-compat:<slot>. Binaries like +# ffmpeg will be found under <prefix>/bin if needed. +ffmpeg_compat_get_prefix() { + (( ${#} == 1 )) || die "Usage: ${FUNCNAME} <slot>" + + echo "${EPREFIX}/usr/lib/ffmpeg${1}" +} + +# @FUNCTION: ffmpeg_compat_setup +# @USAGE: <slot> +# @DESCRIPTION: +# Add ESYSROOT's ffmpeg-compat:<slot> to PKG_CONFIG_PATH for the +# current ABI. Can be called multiple times for multilib. +ffmpeg_compat_setup() { + (( ${#} == 1 )) || die "Usage: ${FUNCNAME} <slot>" + + local path=${SYSROOT}$(ffmpeg_compat_get_prefix "${1}") + [[ ${PKG_CONFIG_PATH} =~ (.*)"${path}"/[^/]+/pkgconfig:(.*) ]] && + PKG_CONFIG_PATH=${BASH_REMATCH[1]}${BASH_REMATCH[2]} + export PKG_CONFIG_PATH=${path}/$(get_libdir)/pkgconfig:${PKG_CONFIG_PATH} +} + +fi -- 2.48.1
