Following bug #501330 I've used user_patch portage's feature to perform checks. Oryginally patch was placed into /etc/portage/patches/dev-libs/glib-2.38.2/ directory. For 2.38.2 version it worked fine. # ebuild /usr/portage/gentoo/dev-libs/glib/glib-2.38.2.ebuild prepare … >>> Preparing source in /var/tmp/portage/dev-libs/glib-2.38.2/work/glib-2.38.2 ... * Applying glib-2.12.12-fbsd.patch ... [ ok ] * Applying glib-2.34.0-testsuite-skip-thread4.patch ... [ ok ] * Applying glib-2.37.x-external-gdbus-codegen.patch ... [ ok ] * Applying glib-2.36.4-znodelete.patch ... [ ok ] * Applying glib-2.38.2-configure.patch ... [ ok ] * Applying user patches from /etc/portage/patches//dev-libs/glib-2.38.2 ... * uninitialized_memory.patch ... [ ok ] * Done with patching * Running eautoreconf in '/var/tmp/portage/dev-libs/glib-2.38.2/work/glib-2.38.2' ... * Skipping 'gtkdocize --copy' due gtkdocize not installed * Running libtoolize --install --copy --force --automake ... … But it dev-libs/glib-2.38.2 is ${P} value, so portage tries to apply patch on all revisions. So, emerge dev-libs/glib-2.38.2_r1 reasonably fails on applying user_patch. According to man 5 ebuild: "PR Contains the revision number or 'r0' if no revision number exists." Willing to apply this patch _only_ to dev-libs/glib-2.38.2, not to dev-libs/glib-2.38.2_r1 and following, I've switched to usage ${PVR} namind and renamed user_patch directory to /etc/portage/patches/dev-libs/glib-2.38.2_r0/ But in this case portage skips applying userpatch: /etc/portage/patches/dev-libs/glib-2.38.2_r0/uninitialized_memory.patch # ebuild /usr/portage/gentoo/dev-libs/glib/glib-2.38.2.ebuild prepare … >>> Preparing source in /var/tmp/portage/dev-libs/glib-2.38.2/work/glib-2.38.2 ... * Applying glib-2.12.12-fbsd.patch ... [ ok ] * Applying glib-2.34.0-testsuite-skip-thread4.patch ... [ ok ] * Applying glib-2.37.x-external-gdbus-codegen.patch ... [ ok ] * Applying glib-2.36.4-znodelete.patch ... [ ok ] * Applying glib-2.38.2-configure.patch ... [ ok ] * Running eautoreconf in '/var/tmp/portage/dev-libs/glib-2.38.2/work/glib-2.38.2' ... * Skipping 'gtkdocize --copy' due gtkdocize not installed * Running libtoolize --install --copy --force --automake ... … My system $ einfo Portage 2.2.8-r1 (default/linux/amd64/13.0, gcc-4.7.3, glibc-2.17, 3.10.25-aufs x86_64) ================================================================= System uname: Linux-3.10.25-aufs-x86_64-AMD_Athlon-tm-_II_X2_250_Processor-with-gentoo-2.2 KiB Mem: 1794820 total, 253404 free KiB Swap: 8000364 total, 8000060 free Timestamp of tree: Mon, 17 Mar 2014 04:15:01 +0000 ld GNU ld (GNU Binutils) 2.23.2 app-shells/bash: 4.2_p45 dev-java/java-config: 2.2.0 dev-lang/python: 2.7.5-r3, 3.3.3 dev-util/cmake: 2.8.11.2 dev-util/pkgconfig: 0.28 sys-apps/baselayout: 2.2 sys-apps/openrc: 0.12.4 sys-apps/sandbox: 2.6-r1 sys-devel/autoconf: 2.13, 2.69 sys-devel/automake: 1.11.6, 1.12.6, 1.13.4 sys-devel/binutils: 2.23.2 sys-devel/gcc: 4.7.3-r1 sys-devel/gcc-config: 1.7.3 sys-devel/libtool: 2.4.2 sys-devel/make: 3.82-r4 sys-kernel/linux-headers: 3.9 (virtual/os-headers) sys-libs/glibc: 2.17 Repositories: gentoo local_hdd ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="* -@EULA" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=native -O2 -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /etc/env.d /usr/share/gnupg/qualified.txt /var/bind" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/php/apache2-php5.4/ext-active/ /etc/php/apache2-php5.5/ext-active/ /etc/php/cgi-php5.4/ext-active/ /etc/php/cgi-php5.5/ext-active/ /etc/php/cli-php5.4/ext-active/ /etc/php/cli-php5.5/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c" CXXFLAGS="-march=native -O2 -pipe" DISTDIR="/usr/portage/distfiles" EMERGE_DEFAULT_OPTS="--ask --verbose --autounmask=n" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-logs buildsyspkg config-protect-if-modified distlocks downgrade-backup ebuild-locks fixlafiles merge-sync news parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync" FFLAGS="-O2 -pipe" GENTOO_MIRRORS="http://mirror.yandex.ru/gentoo-distfiles/ ftp://mirror.yandex.ru/gentoo-distfiles/ http://ftp.corbina.net/pub/Linux/gentoo/ ftp://ftp.corbina.net/pub/Linux/gentoo/" LANG="ru_RU.utf8" LC_ALL="" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j2" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_EXTRA_OPTS="--exclude-from=/etc/portage/rsync_excludes" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage/gentoo" PORTDIR_OVERLAY="/usr/portage/local" USE="X a52 ac3 acl alsa amd64 avi berkdb bold bzip2 cdr cli consolekit cracklib crypt cups cxx dbus djvu dri dvd flac fortran gdbm gif gtk iconv inotify jpeg jpeg2k lock mmx modules mp3 multilib ncurses nls nptl ogg openmp pam pcre pdf png policykit qt3support readline session sse sse2 ssl tcpd thunar tiff udev udisks unicode utf8 vorbis xcb xulrunner zlib" ABI_X86="64" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump author" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LINGUAS="ru ru_RU" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-4" PYTHON_SINGLE_TARGET="python2_7" PYTHON_TARGETS="python2_7 python3_3" RUBY_TARGETS="ruby19 ruby20" USERLAND="GNU" VIDEO_CARDS="radeon" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CPPFLAGS, CTARGET, INSTALL_MASK, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, USE_PYTHON
`man 5 eutils.eclass` already documents: The patches are taken from /etc/portage/patches/<CATEGORY>/<PF|P|PN>[:SLOT]/ but it doesn't support patches specific for $P-r0 at this time
the source already supports $P-r0: ${CATEGORY}/{${P}-${PR},${P},${PN}}{,:${SLOT}} i've updated the documentation accordingly: http://sources.gentoo.org/eclass/eutils.eclass?r1=1.433&r2=1.434
