diff --git a/www-client/icecat/Manifest b/www-client/icecat/Manifest
index 5093a6d..c9e81b3 100644
--- a/www-client/icecat/Manifest
+++ b/www-client/icecat/Manifest
@@ -1,4 +1,6 @@
 DIST firefox-78esr-patches-18.tar.xz 55968 BLAKE2B f32fe8e0086e4bf74fd43127b9fe136a0e0ad6e51cb8a2398f6e8f9fe585de1574c745dd3f50440cf62b626f9fa24d368284c563fb75acbacc5238f9bc8d099f SHA512 99a51a241d91aa00c64550f2a521528f6134c8812e379eaf95cd1287fd51d00346de8d41f2d2f55a83332580531b31c4e814a47d7f69da6e3512613e8e98bb31
 DIST firefox-91esr-patches-01.tar.xz 20768 BLAKE2B 22ebd261b445f1920448d9243e3e15ed2e4d393099552bf43f26c9705dd00f8b87b5720e94fc43a31dd96c3a88398e17da80f81953f0bf9658d75e4a85a31fc9 SHA512 5935545535366abf8681286a9bd745f95f83ebf0d69ba5ce600ae513a4391fc16ea7eb4addbe8ad27f97eae3c1fcb05a78e2fc0fbd4cbf7798a83b778b5e1535
+DIST firefox-91esr-patches-02.tar.xz 16900 BLAKE2B 6b8ca8bca3c35c6ea80b947610906e36883522e265e655a18c16ae3d62512de8c2b68666639a65c45d4d2949047994bbd4fb5506b1062441ac4774b14291e0c5 SHA512 7382ed736b830a260cfb78a14c8c34409741949f9fdcc95d4cae2cb0f0b2909b6fff3a3acf32209528c07aed89cc275ee37c76e34fec1c89a920662ad42a3bfe
 DIST icecat-78.15.0-gnu1.tar.bz2 511801347 BLAKE2B c6d3fcda272c064b038306619619a95e0c18e12ef792c77d18ae0a9ecbe69b46b79f4576a577265da353cf93a45f17ccd8c618bfddad932bc246558f774d5d0c SHA512 a80869e09baf3847aeb381c041c74e4c8305dd316877016b0be7fe272ca864fd3d9209ba15b62b069bd6c68c6cf40da0dc329cbf8321e82b7be57e3122f9cc41
 DIST icecat-91.3.0-gnu1.tar.bz2 561049089 BLAKE2B c179ee75f47d6df2c2c3cd141c4271690857f98a876a38e12925b8fe5c3149df87d73a537e8a933fbf2aae4d12d2856a6e95280b4304c47c11e35f4508cda375 SHA512 fd8cc1fb6754d97325eb26fac4d6dbd42c1cc395cf00d8e61c4ecc1f4f53884b4a9d2673c1ccc8f30f4bcb00d62eafe9836f52140507366f1b120b0494dfb70e
+DIST icecat-91.4.0-gnu1.tar.bz2 561745990 BLAKE2B 54c4f939512fc6c2925dd466214d9cb52eb98d7057f4c383a447697845824409ff9523c61330aef60b721066f34b5078b63980cd07ce4c5a1f76109a03b746c1 SHA512 11d311fd88634ec8be519241ac18a09a97b884f6b73b78aa8ac05ec65afae364e598b130d2af36a4c20d02c7f9f34a936eee12bacedc209c545ba25a1f14c17d
diff --git a/www-client/icecat/icecat-91.4.0.ebuild b/www-client/icecat/icecat-91.4.0.ebuild
new file mode 100644
index 0000000..3a884e6
--- /dev/null
+++ b/www-client/icecat/icecat-91.4.0.ebuild
@@ -0,0 +1,1118 @@
+# Copyright 1999-2021 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+# Ebuild is based on the Firefox ebuilds in the main repo
+
+EAPI="7"
+
+# Using Gentoos firefox patches as system libraries and lto are quite nice
+FIREFOX_PATCHSET="firefox-91esr-patches-02.tar.xz"
+
+LLVM_MAX_SLOT=13
+
+PYTHON_COMPAT=( python3_{7..10} )
+PYTHON_REQ_USE="ncurses,sqlite,ssl"
+
+WANT_AUTOCONF="2.1"
+
+VIRTUALX_REQUIRED="pgo"
+
+inherit autotools check-reqs desktop flag-o-matic gnome2-utils linux-info \
+	llvm multiprocessing pax-utils python-any-r1 toolchain-funcs \
+	virtualx xdg
+
+PATCH_URIS=(
+	https://dev.gentoo.org/~{polynomial-c,whissi}/mozilla/patchsets/${FIREFOX_PATCHSET}
+)
+
+SRC_URI="
+	!buildtarball? ( icecat-${PV}-gnu1.tar.bz2 )
+	${PATCH_URIS[@]}
+"
+
+DESCRIPTION="GNU IceCat Web Browser"
+HOMEPAGE="https://www.gnu.org/software/gnuzilla/"
+
+KEYWORDS="~amd64"
+
+SLOT="0"
+LICENSE="MPL-2.0 GPL-2 LGPL-2.1"
+IUSE="+clang cpu_flags_arm_neon dbus debug +buildtarball geckodriver
+	hardened hwaccel jack lto +openh264 pgo pulseaudio screencast selinux
+	+system-av1 +system-harfbuzz +system-icu +system-jpeg +system-libevent
+	+system-libvpx +system-webp wayland wifi"
+
+IUSE="+clang cpu_flags_arm_neon dbus debug +buildtarball hardened hwaccel"
+IUSE+=" jack lto +openh264 pgo pulseaudio sndio selinux"
+IUSE+=" +system-av1 +system-harfbuzz +system-icu +system-jpeg +system-libevent +system-libvpx +system-webp"
+IUSE+=" wayland wifi"
+
+# Firefox-only IUSE
+IUSE+=" geckodriver"
+IUSE+=" screencast"
+
+REQUIRED_USE="debug? ( !system-av1 )
+	wifi? ( dbus )"
+
+# Firefox-only REQUIRED_USE flags
+REQUIRED_USE+=" screencast? ( wayland )"
+
+BDEPEND="${PYTHON_DEPS}
+	app-arch/unzip
+	app-arch/zip
+	>=dev-util/cbindgen-0.19.0
+	>=net-libs/nodejs-10.23.1
+	virtual/pkgconfig
+	>=virtual/rust-1.51.0
+	|| (
+		(
+			sys-devel/clang:13
+			sys-devel/llvm:13
+			clang? (
+				=sys-devel/lld-13*
+				pgo? ( =sys-libs/compiler-rt-sanitizers-13*[profile] )
+			)
+		)
+		(
+			sys-devel/clang:12
+			sys-devel/llvm:12
+			clang? (
+				=sys-devel/lld-12*
+				pgo? ( =sys-libs/compiler-rt-sanitizers-12*[profile] )
+			)
+		)
+		(
+			sys-devel/clang:11
+			sys-devel/llvm:11
+			clang? (
+				=sys-devel/lld-11*
+				pgo? ( =sys-libs/compiler-rt-sanitizers-11*[profile] )
+			)
+		)
+	)
+	amd64? ( >=dev-lang/nasm-2.13 )
+	x86? ( >=dev-lang/nasm-2.13 )
+	buildtarball? ( ~www-client/makeicecat-"${PV}"[buildtarball] )"
+
+CDEPEND="
+	>=dev-libs/nss-3.68
+	>=dev-libs/nspr-4.32
+	dev-libs/atk
+	dev-libs/expat
+	>=x11-libs/cairo-1.10[X]
+	>=x11-libs/gtk+-3.4.0:3[X]
+	x11-libs/gdk-pixbuf
+	>=x11-libs/pango-1.22.0
+	>=media-libs/libpng-1.6.35:0=[apng]
+	>=media-libs/mesa-10.2:*
+	media-libs/fontconfig
+	>=media-libs/freetype-2.4.10
+	kernel_linux? ( !pulseaudio? ( media-libs/alsa-lib ) )
+	virtual/freedesktop-icon-theme
+	>=x11-libs/pixman-0.19.2
+	>=dev-libs/glib-2.26:2
+	>=sys-libs/zlib-1.2.3
+	>=dev-libs/libffi-3.0.10:=
+	media-video/ffmpeg
+	x11-libs/libX11
+	x11-libs/libxcb
+	x11-libs/libXcomposite
+	x11-libs/libXdamage
+	x11-libs/libXext
+	x11-libs/libXfixes
+	x11-libs/libXrender
+	x11-libs/libXt
+	dbus? (
+		sys-apps/dbus
+		dev-libs/dbus-glib
+	)
+	screencast? ( media-video/pipewire:0/0.3 )
+	system-av1? (
+		>=media-libs/dav1d-0.8.1:=
+		>=media-libs/libaom-1.0.0:=
+	)
+	system-harfbuzz? (
+		>=media-libs/harfbuzz-2.8.1:0=
+		>=media-gfx/graphite2-1.3.13
+	)
+	system-icu? ( >=dev-libs/icu-69.1:= )
+	system-jpeg? ( >=media-libs/libjpeg-turbo-1.2.1 )
+	system-libevent? ( >=dev-libs/libevent-2.0:0=[threads] )
+	system-libvpx? ( >=media-libs/libvpx-1.8.2:0=[postproc] )
+	system-webp? ( >=media-libs/libwebp-1.1.0:0= )
+	wifi? (
+		kernel_linux? (
+			sys-apps/dbus
+			dev-libs/dbus-glib
+			net-misc/networkmanager
+		)
+	)
+	jack? ( virtual/jack )
+	selinux? ( sec-policy/selinux-mozilla )
+	sndio? ( media-sound/sndio )"
+
+RDEPEND="${CDEPEND}
+	jack? ( virtual/jack )
+	openh264? ( media-libs/openh264:*[plugin] )
+	pulseaudio? (
+		|| (
+			media-sound/pulseaudio
+			>=media-sound/apulse-0.1.12-r4
+		)
+	)
+	selinux? ( sec-policy/selinux-mozilla )"
+
+DEPEND="${CDEPEND}
+	x11-libs/libICE
+	x11-libs/libSM
+	pulseaudio? (
+		|| (
+			media-sound/pulseaudio
+			>=media-sound/apulse-0.1.12-r4[sdk]
+		)
+	)
+	wayland? ( >=x11-libs/gtk+-3.11:3[wayland] )
+	amd64? ( virtual/opengl )
+	x86? ( virtual/opengl )"
+
+S="${WORKDIR}/${PN}-${PV%_*}"
+
+llvm_check_deps() {
+	if ! has_version -b "sys-devel/clang:${LLVM_SLOT}" ; then
+		einfo "sys-devel/clang:${LLVM_SLOT} is missing! Cannot use LLVM slot ${LLVM_SLOT} ..." >&2
+		return 1
+	fi
+
+	if use clang ; then
+		if ! has_version -b "=sys-devel/lld-${LLVM_SLOT}*" ; then
+			einfo "=sys-devel/lld-${LLVM_SLOT}* is missing! Cannot use LLVM slot ${LLVM_SLOT} ..." >&2
+			return 1
+		fi
+
+		if use pgo ; then
+			if ! has_version -b "=sys-libs/compiler-rt-sanitizers-${LLVM_SLOT}*" ; then
+				einfo "=sys-libs/compiler-rt-sanitizers-${LLVM_SLOT}* is missing! Cannot use LLVM slot ${LLVM_SLOT} ..." >&2
+				return 1
+			fi
+		fi
+	fi
+
+	einfo "Using LLVM slot ${LLVM_SLOT} to build" >&2
+}
+
+MOZ_LANGS=(
+	af ar ast be bg br ca cak cs cy da de dsb
+	el en-CA en-GB en-US es-AR es-ES et eu
+	fi fr fy-NL ga-IE gd gl he hr hsb hu
+	id is it ja ka kab kk ko lt lv ms nb-NO nl nn-NO
+	pa-IN pl pt-BR pt-PT rm ro ru
+	sk sl sq sr sv-SE th tr uk uz vi zh-CN zh-TW
+)
+
+# Firefox-only LANGS
+MOZ_LANGS+=( ach )
+MOZ_LANGS+=( an )
+MOZ_LANGS+=( az )
+MOZ_LANGS+=( bn )
+MOZ_LANGS+=( bs )
+MOZ_LANGS+=( ca-valencia )
+MOZ_LANGS+=( eo )
+MOZ_LANGS+=( es-CL )
+MOZ_LANGS+=( es-MX )
+MOZ_LANGS+=( fa )
+MOZ_LANGS+=( ff )
+MOZ_LANGS+=( gn )
+MOZ_LANGS+=( gu-IN )
+MOZ_LANGS+=( hi-IN )
+MOZ_LANGS+=( hy-AM )
+MOZ_LANGS+=( ia )
+MOZ_LANGS+=( km )
+MOZ_LANGS+=( kn )
+MOZ_LANGS+=( lij )
+MOZ_LANGS+=( mk )
+MOZ_LANGS+=( mr )
+MOZ_LANGS+=( my )
+MOZ_LANGS+=( ne-NP )
+MOZ_LANGS+=( oc )
+MOZ_LANGS+=( sco )
+MOZ_LANGS+=( si )
+MOZ_LANGS+=( son )
+MOZ_LANGS+=( szl )
+MOZ_LANGS+=( ta )
+MOZ_LANGS+=( te )
+MOZ_LANGS+=( tl )
+MOZ_LANGS+=( trs )
+MOZ_LANGS+=( ur )
+MOZ_LANGS+=( xh )
+
+mozilla_set_globals() {
+	# https://bugs.gentoo.org/587334
+	local MOZ_TOO_REGIONALIZED_FOR_L10N=(
+		fy-NL ga-IE gu-IN hi-IN hy-AM nb-NO ne-NP nn-NO pa-IN sv-SE
+	)
+
+	local lang xflag
+	for lang in "${MOZ_LANGS[@]}" ; do
+		# en and en_US are handled internally
+		if [[ ${lang} == en ]] || [[ ${lang} == en-US ]] ; then
+			continue
+		fi
+
+		# strip region subtag if $lang is in the list
+		if has ${lang} "${MOZ_TOO_REGIONALIZED_FOR_L10N[@]}" ; then
+			xflag=${lang%%-*}
+		else
+			xflag=${lang}
+		fi
+
+		IUSE+=" l10n_${xflag/[_@]/-}"
+	done
+
+}
+mozilla_set_globals
+
+moz_clear_vendor_checksums() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	if [[ ${#} -ne 1 ]] ; then
+		die "${FUNCNAME} requires exact one argument"
+	fi
+
+	einfo "Clearing cargo checksums for ${1} ..."
+
+	sed -i \
+		-e 's/\("files":{\)[^}]*/\1/' \
+		"${S}"/third_party/rust/${1}/.cargo-checksum.json \
+		|| die
+}
+
+moz_build_xpi() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	local MOZ_TOO_REGIONALIZED_FOR_L10N=(
+		fy-NL ga-IE gu-IN hi-IN hy-AM nb-NO ne-NP nn-NO pa-IN sv-SE
+	)
+
+	cd "${BUILD_DIR}"/browser/locales || die
+	local lang xflag
+	for lang in "${MOZ_LANGS[@]}"; do
+		# en and en_US are handled internally
+		if [[ ${lang} == en ]] || [[ ${lang} == en-US ]] ; then
+			continue
+		fi
+
+		# strip region subtag if $lang is in the list
+		if has ${lang} "${MOZ_TOO_REGIONALIZED_FOR_L10N[@]}" ; then
+			xflag=${lang%%-*}
+		else
+			xflag=${lang}
+		fi
+
+		if use l10n_"${xflag}"; then
+			emake langpack-"${lang}" LOCALE_MERGEDIR=.
+		fi
+	done
+}
+
+moz_install_xpi() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	if [[ ${#} -lt 2 ]] ; then
+		die "${FUNCNAME} requires at least two arguments"
+	fi
+
+	local DESTDIR=${1}
+	shift
+
+	insinto "${DESTDIR}"
+
+	local emid xpi_file xpi_tmp_dir
+	for xpi_file in "${@}" ; do
+		emid=
+		xpi_tmp_dir=$(mktemp -d --tmpdir="${T}")
+
+		# Unpack XPI
+		unzip -qq "${xpi_file}" -d "${xpi_tmp_dir}" || die
+
+		# Determine extension ID
+		if [[ -f "${xpi_tmp_dir}/install.rdf" ]] ; then
+			emid=$(sed -n -e '/install-manifest/,$ { /em:id/!d; s/.*[\">]\([^\"<>]*\)[\"<].*/\1/; p; q }' "${xpi_tmp_dir}/install.rdf")
+			[[ -z "${emid}" ]] && die "failed to determine extension id from install.rdf"
+		elif [[ -f "${xpi_tmp_dir}/manifest.json" ]] ; then
+			emid=$(sed -n -e 's/.*"id": "\([^"]*\)".*/\1/p' "${xpi_tmp_dir}/manifest.json")
+			[[ -z "${emid}" ]] && die "failed to determine extension id from manifest.json"
+		else
+			die "failed to determine extension id"
+		fi
+
+		einfo "Installing ${emid}.xpi into ${ED}${DESTDIR} ..."
+		newins "${xpi_file}" "${emid}.xpi"
+	done
+}
+
+mozconfig_add_options_ac() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	if [[ ${#} -lt 2 ]] ; then
+		die "${FUNCNAME} requires at least two arguments"
+	fi
+
+	local reason=${1}
+	shift
+
+	local option
+	for option in ${@} ; do
+		echo "ac_add_options ${option} # ${reason}" >>${MOZCONFIG}
+	done
+}
+
+mozconfig_add_options_mk() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	if [[ ${#} -lt 2 ]] ; then
+		die "${FUNCNAME} requires at least two arguments"
+	fi
+
+	local reason=${1}
+	shift
+
+	local option
+	for option in ${@} ; do
+		echo "mk_add_options ${option} # ${reason}" >>${MOZCONFIG}
+	done
+}
+
+mozconfig_use_enable() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	if [[ ${#} -lt 1 ]] ; then
+		die "${FUNCNAME} requires at least one arguments"
+	fi
+
+	local flag=$(use_enable "${@}")
+	mozconfig_add_options_ac "$(use ${1} && echo +${1} || echo -${1})" "${flag}"
+}
+
+mozconfig_use_with() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	if [[ ${#} -lt 1 ]] ; then
+		die "${FUNCNAME} requires at least one arguments"
+	fi
+
+	local flag=$(use_with "${@}")
+	mozconfig_add_options_ac "$(use ${1} && echo +${1} || echo -${1})" "${flag}"
+}
+
+pkg_pretend() {
+	if [[ ${MERGE_TYPE} != binary ]] ; then
+		if use pgo ; then
+			if ! has usersandbox $FEATURES ; then
+				die "You must enable usersandbox as X server can not run as root!"
+			fi
+		fi
+
+		# Ensure we have enough disk space to compile
+		if use pgo || use lto || use debug ; then
+			CHECKREQS_DISK_BUILD="13500M"
+		else
+			CHECKREQS_DISK_BUILD="6400M"
+		fi
+
+		check-reqs_pkg_pretend
+	fi
+}
+
+pkg_nofetch() {
+	if ! use buildtarball; then
+		einfo "You have not enabled buildtarball use flag, therefore you will have to"
+		einfo "build the tarball manually and place it in your distfiles directory."
+		einfo "You may find the script for building the tarball here"
+		einfo "https://git.savannah.gnu.org/cgit/gnuzilla.git/, but make sure it is the"
+		einfo "right version."
+		einfo "The output of the script should be icecat-"${PV}"-gnu1.tar.bz2"
+	fi
+}
+
+pkg_setup() {
+	if [[ ${MERGE_TYPE} != binary ]] ; then
+		if use pgo ; then
+			if ! has userpriv ${FEATURES} ; then
+				eerror "Building ${PN} with USE=pgo and FEATURES=-userpriv is not supported!"
+			fi
+		fi
+
+		# Ensure we have enough disk space to compile
+		if use pgo || use lto || use debug ; then
+			CHECKREQS_DISK_BUILD="13500M"
+		else
+			CHECKREQS_DISK_BUILD="6400M"
+		fi
+
+		check-reqs_pkg_setup
+
+		llvm_pkg_setup
+
+		if use clang && use lto ; then
+			local version_lld=$(ld.lld --version 2>/dev/null | awk '{ print $2 }')
+			[[ -n ${version_lld} ]] && version_lld=$(ver_cut 1 "${version_lld}")
+			[[ -z ${version_lld} ]] && die "Failed to read ld.lld version!"
+
+			# temp fix for https://bugs.gentoo.org/768543
+			# we can assume that rust 1.{49,50}.0 always uses llvm 11
+			local version_rust=$(rustc -Vv 2>/dev/null | grep -F -- 'release:' | awk '{ print $2 }')
+			[[ -n ${version_rust} ]] && version_rust=$(ver_cut 1-2 "${version_rust}")
+			[[ -z ${version_rust} ]] && die "Failed to read version from rustc!"
+
+			if ver_test "${version_rust}" -ge "1.49" && ver_test "${version_rust}" -le "1.50" ; then
+				local version_llvm_rust="11"
+			else
+				local version_llvm_rust=$(rustc -Vv 2>/dev/null | grep -F -- 'LLVM version:' | awk '{ print $3 }')
+				[[ -n ${version_llvm_rust} ]] && version_llvm_rust=$(ver_cut 1 "${version_llvm_rust}")
+				[[ -z ${version_llvm_rust} ]] && die "Failed to read used LLVM version from rustc!"
+			fi
+
+			if ver_test "${version_lld}" -ne "${version_llvm_rust}" ; then
+				eerror "Rust is using LLVM version ${version_llvm_rust} but ld.lld version belongs to LLVM version ${version_lld}."
+				eerror "You will be unable to link ${CATEGORY}/${PN}. To proceed you have the following options:"
+				eerror "  - Manually switch rust version using 'eselect rust' to match used LLVM version"
+				eerror "  - Switch to dev-lang/rust[system-llvm] which will guarantee matching version"
+				eerror "  - Build ${CATEGORY}/${PN} without USE=lto"
+				die "LLVM version used by Rust (${version_llvm_rust}) does not match with ld.lld version (${version_lld})!"
+			fi
+		fi
+
+		if ! use clang && [[ $(gcc-major-version) -eq 11 ]] \
+			&& ! has_version -b ">sys-devel/gcc-11.1.0:11" ; then
+			# bug 792705
+			eerror "Using GCC 11 to compile firefox is currently known to be broken (see bug #792705)."
+			die "Set USE=clang or select <gcc-11 to build ${CATEGORY}/${P}."
+		fi
+
+		python-any-r1_pkg_setup
+
+		# Avoid PGO profiling problems due to enviroment leakage
+		# These should *always* be cleaned up anyway
+		unset \
+			DBUS_SESSION_BUS_ADDRESS \
+			DISPLAY \
+			ORBIT_SOCKETDIR \
+			SESSION_MANAGER \
+			XAUTHORITY \
+			XDG_CACHE_HOME \
+			XDG_SESSION_COOKIE
+
+		# Build system is using /proc/self/oom_score_adj, bug #604394
+		addpredict /proc/self/oom_score_adj
+
+		if use pgo ; then
+			# Allow access to GPU during PGO run
+			local ati_cards mesa_cards nvidia_cards render_cards
+			shopt -s nullglob
+
+			ati_cards=$(echo -n /dev/ati/card* | sed 's/ /:/g')
+			if [[ -n "${ati_cards}" ]] ; then
+				addpredict "${ati_cards}"
+			fi
+
+			mesa_cards=$(echo -n /dev/dri/card* | sed 's/ /:/g')
+			if [[ -n "${mesa_cards}" ]] ; then
+				addpredict "${mesa_cards}"
+			fi
+
+			nvidia_cards=$(echo -n /dev/nvidia* | sed 's/ /:/g')
+			if [[ -n "${nvidia_cards}" ]] ; then
+				addpredict "${nvidia_cards}"
+			fi
+
+			render_cards=$(echo -n /dev/dri/renderD128* | sed 's/ /:/g')
+			if [[ -n "${render_cards}" ]] ; then
+				addpredict "${render_cards}"
+			fi
+
+			shopt -u nullglob
+		fi
+
+		if ! mountpoint -q /dev/shm ; then
+			# If /dev/shm is not available, configure is known to fail with
+			# a traceback report referencing /usr/lib/pythonN.N/multiprocessing/synchronize.py
+			ewarn "/dev/shm is not mounted -- expect build failures!"
+		fi
+
+		# Ensure we use C locale when building, bug #746215
+		export LC_ALL=C
+	fi
+	linux-info_pkg_setup
+}
+
+src_unpack() {
+	if use buildtarball; then
+		unpack /usr/src/makeicecat-"${PV}"/output/icecat-"${PV}"-gnu1.tar.bz2 || eerror "Tarball is missing, check that www-client/makeicecat has use flag buildtarball enabled."
+	else
+		unpack icecat-"${PV}"-gnu1.tar.bz2
+	fi
+	unpack "${FIREFOX_PATCHSET}"
+}
+
+src_prepare() {
+	use lto && rm -v "${WORKDIR}"/firefox-patches/*-LTO-Only-enable-LTO-*.patch
+	eapply "${WORKDIR}/firefox-patches"
+
+	# Allow user to apply any additional patches without modifing ebuild
+	eapply_user
+
+	# Make LTO respect MAKEOPTS
+	sed -i \
+		-e "s/multiprocessing.cpu_count()/$(makeopts_jobs)/" \
+		"${S}"/build/moz.configure/lto-pgo.configure \
+		|| die "sed failed to set num_cores"
+
+	# Make ICU respect MAKEOPTS
+	sed -i \
+		-e "s/multiprocessing.cpu_count()/$(makeopts_jobs)/" \
+		"${S}"/intl/icu_sources_data.py \
+		|| die "sed failed to set num_cores"
+
+	# sed-in toolchain prefix
+	sed -i \
+		-e "s/objdump/${CHOST}-objdump/" \
+		"${S}"/python/mozbuild/mozbuild/configure/check_debug_ranges.py \
+		|| die "sed failed to set toolchain prefix"
+
+	sed -i \
+		-e 's/ccache_stats = None/return None/' \
+		"${S}"/python/mozbuild/mozbuild/controller/building.py \
+		|| die "sed failed to disable ccache stats call"
+
+	einfo "Removing pre-built binaries ..."
+	find "${S}"/third_party -type f \( -name '*.so' -o -name '*.o' \) -print -delete || die
+
+	# Clearing checksums where we have applied patches
+	moz_clear_vendor_checksums target-lexicon-0.9.0
+
+	# Create build dir
+	BUILD_DIR="${WORKDIR}/${PN}_build"
+	mkdir -p "${BUILD_DIR}" || die
+
+	xdg_src_prepare
+}
+
+src_configure() {
+	# Show flags set at the beginning
+	einfo "Current BINDGEN_CFLAGS:\t${BINDGEN_CFLAGS:-no value set}"
+	einfo "Current CFLAGS:\t\t${CFLAGS:-no value set}"
+	einfo "Current CXXFLAGS:\t\t${CXXFLAGS:-no value set}"
+	einfo "Current LDFLAGS:\t\t${LDFLAGS:-no value set}"
+	einfo "Current RUSTFLAGS:\t\t${RUSTFLAGS:-no value set}"
+
+	local have_switched_compiler=
+	if use clang && ! tc-is-clang ; then
+		# Force clang
+		einfo "Enforcing the use of clang due to USE=clang ..."
+		have_switched_compiler=yes
+		AR=llvm-ar
+		CC=${CHOST}-clang
+		CXX=${CHOST}-clang++
+		NM=llvm-nm
+		RANLIB=llvm-ranlib
+	elif ! use clang && ! tc-is-gcc ; then
+		# Force gcc
+		have_switched_compiler=yes
+		einfo "Enforcing the use of gcc due to USE=-clang ..."
+		AR=gcc-ar
+		CC=${CHOST}-gcc
+		CXX=${CHOST}-g++
+		NM=gcc-nm
+		RANLIB=gcc-ranlib
+	fi
+
+	if [[ -n "${have_switched_compiler}" ]] ; then
+		# Because we switched active compiler we have to ensure
+		# that no unsupported flags are set
+		strip-unsupported-flags
+	fi
+
+	# Ensure we use correct toolchain
+	export HOST_CC="$(tc-getBUILD_CC)"
+	export HOST_CXX="$(tc-getBUILD_CXX)"
+	tc-export CC CXX LD AR NM OBJDUMP RANLIB PKG_CONFIG
+
+	# Pass the correct toolchain paths through cbindgen
+	if tc-is-cross-compiler ; then
+		export BINDGEN_CFLAGS="${SYSROOT:+--sysroot=${ESYSROOT}} --target=${CHOST} ${BINDGEN_CFLAGS-}"
+	fi
+
+	# Set MOZILLA_FIVE_HOME
+	export MOZILLA_FIVE_HOME="/usr/$(get_libdir)/${PN}"
+
+	# python/mach/mach/mixin/process.py fails to detect SHELL
+	export SHELL="${EPREFIX}/bin/bash"
+
+	# Set MOZCONFIG
+	export MOZCONFIG="${S}/.mozconfig"
+
+	# Initialize MOZCONFIG
+	mozconfig_add_options_ac '' --enable-application=browser
+
+	# Set Gentoo defaults
+	export MOZILLA_OFFICIAL=1
+
+	mozconfig_add_options_ac 'Gentoo default' \
+		--allow-addon-sideload \
+		--disable-cargo-incremental \
+		--disable-crashreporter \
+		--disable-eme \
+		--disable-install-strip \
+		--disable-strip \
+		--disable-updater \
+		--enable-official-branding \
+		--enable-release \
+		--enable-system-ffi \
+		--enable-system-pixman \
+		--host="${CBUILD:-${CHOST}}" \
+		--libdir="${EPREFIX}/usr/$(get_libdir)" \
+		--prefix="${EPREFIX}/usr" \
+		--target="${CHOST}" \
+		--without-ccache \
+		--with-intl-api \
+		--with-l10n-base="${S}"/l10n \
+		--with-libclang-path="$(llvm-config --libdir)" \
+		--with-system-nspr \
+		--with-system-nss \
+		--with-system-png \
+		--with-system-zlib \
+		--with-toolchain-prefix="${CHOST}-" \
+		--with-unsigned-addon-scopes=app,system \
+		--x-includes="${SYSROOT}${EPREFIX}/usr/include" \
+		--x-libraries="${SYSROOT}${EPREFIX}/usr/$(get_libdir)"
+
+	if ! use x86 && [[ ${CHOST} != armv*h* ]] ; then
+		mozconfig_add_options_ac '' --enable-rust-simd
+	fi
+
+	mozconfig_use_with system-av1
+	mozconfig_use_with system-harfbuzz
+	mozconfig_use_with system-harfbuzz system-graphite2
+	mozconfig_use_with system-icu
+	mozconfig_use_with system-jpeg
+	mozconfig_use_with system-libevent system-libevent "${SYSROOT}${EPREFIX}/usr"
+	mozconfig_use_with system-libvpx
+	mozconfig_use_with system-webp
+
+	mozconfig_use_enable dbus
+
+	mozconfig_use_enable geckodriver
+
+	if use hardened ; then
+		mozconfig_add_options_ac "+hardened" --enable-hardening
+		append-ldflags "-Wl,-z,relro -Wl,-z,now"
+	fi
+
+	mozconfig_use_enable jack
+
+	mozconfig_use_enable pulseaudio
+	# force the deprecated alsa sound code if pulseaudio is disabled
+	if use kernel_linux && ! use pulseaudio ; then
+		mozconfig_add_options_ac '-pulseaudio' --enable-alsa
+	fi
+
+	mozconfig_use_enable sndio
+
+	mozconfig_use_enable wifi necko-wifi
+
+	if use wayland ; then
+		mozconfig_add_options_ac '+wayland' --enable-default-toolkit=cairo-gtk3-wayland
+	else
+		mozconfig_add_options_ac '' --enable-default-toolkit=cairo-gtk3
+	fi
+
+	if use lto ; then
+		if use clang ; then
+			# Upstream only supports lld when using clang
+			mozconfig_add_options_ac "forcing ld=lld due to USE=clang and USE=lto" --enable-linker=lld
+
+			mozconfig_add_options_ac '+lto' --enable-lto=cross
+		else
+			# ld.gold is known to fail:
+			# /usr/lib/gcc/x86_64-pc-linux-gnu/11.2.1/../../../../x86_64-pc-linux-gnu/bin/ld.gold: internal error in set_xindex, at /var/tmp/portage/sys-devel/binutils-2.37_p1-r1/work/binutils-2.37/gold/object.h:1050
+
+			# ThinLTO is currently broken, see bmo#1644409
+			mozconfig_add_options_ac '+lto' --enable-lto=full
+		fi
+
+		if use pgo ; then
+			mozconfig_add_options_ac '+pgo' MOZ_PGO=1
+
+			if use clang ; then
+				# Used in build/pgo/profileserver.py
+				export LLVM_PROFDATA="llvm-profdata"
+			fi
+		fi
+	else
+		# Avoid auto-magic on linker
+		if use clang ; then
+			# This is upstream's default
+			mozconfig_add_options_ac "forcing ld=lld due to USE=clang" --enable-linker=lld
+		else
+			mozconfig_add_options_ac "linker is set to bfd" --enable-linker=bfd
+		fi
+	fi
+
+	# LTO flag was handled via configure
+	filter-flags '-flto*'
+
+	mozconfig_use_enable debug
+	if use debug ; then
+		mozconfig_add_options_ac '+debug' --disable-optimize
+	else
+		if is-flag '-g*' ; then
+			if use clang ; then
+				mozconfig_add_options_ac 'from CFLAGS' --enable-debug-symbols=$(get-flag '-g*')
+			else
+				mozconfig_add_options_ac 'from CFLAGS' --enable-debug-symbols
+			fi
+		else
+			mozconfig_add_options_ac 'Gentoo default' --disable-debug-symbols
+		fi
+
+		if is-flag '-O0' ; then
+			mozconfig_add_options_ac "from CFLAGS" --enable-optimize=-O0
+		elif is-flag '-O4' ; then
+			mozconfig_add_options_ac "from CFLAGS" --enable-optimize=-O4
+		elif is-flag '-O3' ; then
+			mozconfig_add_options_ac "from CFLAGS" --enable-optimize=-O3
+		elif is-flag '-O1' ; then
+			mozconfig_add_options_ac "from CFLAGS" --enable-optimize=-O1
+		elif is-flag '-Os' ; then
+			mozconfig_add_options_ac "from CFLAGS" --enable-optimize=-Os
+		else
+			mozconfig_add_options_ac "Gentoo default" --enable-optimize=-O2
+		fi
+	fi
+
+	# Debug flag was handled via configure
+	filter-flags '-g*'
+
+	# Optimization flag was handled via configure
+	filter-flags '-O*'
+
+	# Modifications to better support ARM, bug #553364
+	if use cpu_flags_arm_neon ; then
+		mozconfig_add_options_ac '+cpu_flags_arm_neon' --with-fpu=neon
+
+		if ! tc-is-clang ; then
+			# thumb options aren't supported when using clang, bug 666966
+			mozconfig_add_options_ac '+cpu_flags_arm_neon' \
+				--with-thumb=yes \
+				--with-thumb-interwork=no
+		fi
+	fi
+
+	if [[ ${CHOST} == armv*h* ]] ; then
+		mozconfig_add_options_ac 'CHOST=armv*h*' --with-float-abi=hard
+
+		if ! use system-libvpx ; then
+			sed -i \
+				-e "s|softfp|hard|" \
+				"${S}"/media/libvpx/moz.build \
+				|| die
+		fi
+	fi
+
+	if use clang ; then
+		# https://bugzilla.mozilla.org/show_bug.cgi?id=1482204
+		# https://bugzilla.mozilla.org/show_bug.cgi?id=1483822
+		# toolkit/moz.configure Elfhack section: target.cpu in ('arm', 'x86', 'x86_64')
+		local disable_elf_hack=
+		if use amd64 ; then
+			disable_elf_hack=yes
+		elif use x86 ; then
+			disable_elf_hack=yes
+		elif use arm ; then
+			disable_elf_hack=yes
+		fi
+
+		if [[ -n ${disable_elf_hack} ]] ; then
+			mozconfig_add_options_ac 'elf-hack is broken when using Clang' --disable-elf-hack
+		fi
+	elif tc-is-gcc ; then
+		if ver_test $(gcc-fullversion) -ge 10 ; then
+			einfo "Forcing -fno-tree-loop-vectorize to workaround GCC bug, see bug 758446 ..."
+			append-cxxflags -fno-tree-loop-vectorize
+		fi
+	fi
+
+	# Additional ARCH support
+	case "${ARCH}" in
+		arm)
+			# Reduce the memory requirements for linking
+			if use clang ; then
+				# Nothing to do
+				:;
+			elif tc-ld-is-gold || use lto ; then
+				append-ldflags -Wl,--no-keep-memory
+			else
+				append-ldflags -Wl,--no-keep-memory -Wl,--reduce-memory-overheads
+			fi
+			;;
+	esac
+
+	if ! use elibc_glibc ; then
+		mozconfig_add_options_ac '!elibc_glibc' --disable-jemalloc
+	fi
+
+	# Allow elfhack to work in combination with unstripped binaries
+	# when they would normally be larger than 2GiB.
+	append-ldflags "-Wl,--compress-debug-sections=zlib"
+
+	# Make revdep-rebuild.sh happy; Also required for musl
+	append-ldflags -Wl,-rpath="${MOZILLA_FIVE_HOME}",--enable-new-dtags
+
+	# Pass $MAKEOPTS to build system
+	export MOZ_MAKE_FLAGS="${MAKEOPTS}"
+
+	# Use system's Python environment
+	export MACH_USE_SYSTEM_PYTHON=1
+	export PIP_NO_CACHE_DIR=off
+
+	# Disable notification when build system has finished
+	export MOZ_NOSPAM=1
+
+	# Portage sets XARGS environment variable to "xargs -r" by default which
+	# breaks build system's check_prog() function which doesn't support arguments
+	mozconfig_add_options_ac 'Gentoo default' "XARGS=${EPREFIX}/usr/bin/xargs"
+
+	# Set build dir
+	mozconfig_add_options_mk 'Gentoo default' "MOZ_OBJDIR=${BUILD_DIR}"
+
+	# Show flags we will use
+	einfo "Build BINDGEN_CFLAGS:\t${BINDGEN_CFLAGS:-no value set}"
+	einfo "Build CFLAGS:\t\t${CFLAGS:-no value set}"
+	einfo "Build CXXFLAGS:\t\t${CXXFLAGS:-no value set}"
+	einfo "Build LDFLAGS:\t\t${LDFLAGS:-no value set}"
+	einfo "Build RUSTFLAGS:\t\t${RUSTFLAGS:-no value set}"
+
+	# Handle EXTRA_CONF and show summary
+	local ac opt hash reason
+
+	# Apply EXTRA_ECONF entries to $MOZCONFIG
+	if [[ -n ${EXTRA_ECONF} ]] ; then
+		IFS=\! read -a ac <<<${EXTRA_ECONF// --/\!}
+		for opt in "${ac[@]}"; do
+			mozconfig_add_options_ac "EXTRA_ECONF" --${opt#--}
+		done
+	fi
+
+	echo
+	echo "=========================================================="
+	echo "Building ${PF} with the following configuration"
+	grep ^ac_add_options "${MOZCONFIG}" | while read ac opt hash reason; do
+		[[ -z ${hash} || ${hash} == \# ]] \
+			|| die "error reading mozconfig: ${ac} ${opt} ${hash} ${reason}"
+		printf "    %-30s  %s\n" "${opt}" "${reason:-mozilla.org default}"
+	done
+	echo "=========================================================="
+	echo
+
+	./mach configure || die
+}
+
+src_compile() {
+	local virtx_cmd=
+
+	if use pgo ; then
+		virtx_cmd=virtx
+
+		# Reset and cleanup environment variables used by GNOME/XDG
+		gnome2_environment_reset
+
+		addpredict /root
+	fi
+
+	local -x GDK_BACKEND=x11
+
+	${virtx_cmd} ./mach build --verbose \
+		|| die
+
+	# Build language packs
+	moz_build_xpi
+}
+
+src_install() {
+	# xpcshell is getting called during install
+	pax-mark m \
+		"${BUILD_DIR}"/dist/bin/xpcshell \
+		"${BUILD_DIR}"/dist/bin/${PN} \
+		"${BUILD_DIR}"/dist/bin/plugin-container
+
+	DESTDIR="${D}" ./mach install || die
+
+	# Upstream cannot ship symlink but we can (bmo#658850)
+	rm "${ED}${MOZILLA_FIVE_HOME}/${PN}-bin" || die
+	dosym ${PN} ${MOZILLA_FIVE_HOME}/${PN}-bin
+
+	# Don't install llvm-symbolizer from sys-devel/llvm package
+	if [[ -f "${ED}${MOZILLA_FIVE_HOME}/llvm-symbolizer" ]] ; then
+		rm -v "${ED}${MOZILLA_FIVE_HOME}/llvm-symbolizer" || die
+	fi
+
+	# Install policy (currently only used to disable application updates)
+	insinto "${MOZILLA_FIVE_HOME}/distribution"
+	newins "${FILESDIR}"/distribution.ini distribution.ini
+
+	# Install system-wide preferences
+	local PREFS_DIR="${MOZILLA_FIVE_HOME}/browser/defaults/preferences"
+	insinto "${PREFS_DIR}"
+	newins "${FILESDIR}"/gentoo-default-prefs.js gentoo-prefs.js
+
+	local GENTOO_PREFS="${ED}${PREFS_DIR}/gentoo-prefs.js"
+
+	# Set dictionary path to use system hunspell
+	cat >>"${GENTOO_PREFS}" <<-EOF || die "failed to set spellchecker.dictionary_path pref"
+	pref("spellchecker.dictionary_path",       "${EPREFIX}/usr/share/myspell");
+	EOF
+
+	# Set installDistroAddons to true so that language packs work
+	cat >>"${GENTOO_PREFS}" <<-EOF || die "failed to set extensions.installDistroAddons pref"
+	pref("extensions.installDistroAddons",     true);
+	pref("extensions.langpacks.signatures.required",	false);
+	EOF
+
+	# Disable signatures for language packs so that unsigned just built language packs work
+	cat >>"${GENTOO_PREFS}" <<-EOF || die "failed to disable langpacks signatures"
+	pref("extensions.langpacks.signatures.required",	false);
+	EOF
+
+	# Force hwaccel prefs if USE=hwaccel is enabled
+	if use hwaccel ; then
+		cat "${FILESDIR}"/gentoo-hwaccel-prefs.js \
+		>>"${GENTOO_PREFS}" \
+		|| die "failed to add prefs to force hardware-accelerated rendering to all-gentoo.js"
+	fi
+
+	# Force the graphite pref if USE=system-harfbuzz is enabled, since the pref cannot disable it
+	if use system-harfbuzz ; then
+		cat >>"${GENTOO_PREFS}" <<-EOF || die "failed to set gfx.font_rendering.graphite.enabled pref"
+		sticky_pref("gfx.font_rendering.graphite.enabled", true);
+		EOF
+	fi
+
+	# Install language packs
+	local langpacks=( $(find "${BUILD_DIR}"/dist/linux-x86_64/xpi -type f -name '*.xpi') )
+	if [[ -n "${langpacks}" ]] ; then
+		moz_install_xpi "${MOZILLA_FIVE_HOME}/browser/extensions" "${langpacks[@]}"
+	fi
+
+	# Install geckodriver
+	if use geckodriver ; then
+		einfo "Installing geckodriver into ${ED}${MOZILLA_FIVE_HOME} ..."
+		pax-mark m "${BUILD_DIR}"/dist/bin/geckodriver
+		exeinto "${MOZILLA_FIVE_HOME}"
+		doexe "${BUILD_DIR}"/dist/bin/geckodriver
+
+		dosym ${MOZILLA_FIVE_HOME}/geckodriver /usr/bin/geckodriver
+	fi
+
+	# Install icons
+	local icon_srcdir="${S}/browser/branding/official"
+	local icon_symbolic_file="${FILESDIR}/icon/"${PN}"-symbolic.svg"
+
+	insinto /usr/share/icons/hicolor/symbolic/apps
+	newins "${icon_symbolic_file}" "${PN}"-symbolic.svg
+
+	local icon size
+	for icon in "${icon_srcdir}"/default*.png ; do
+		size=${icon%.png}
+		size=${size##*/default}
+
+		if [[ ${size} -eq 48 ]] ; then
+			newicon "${icon}" ${PN}.png
+		fi
+
+		newicon -s ${size} "${icon}" ${PN}.png
+	done
+
+	# Install menu
+	local app_name="GNU IceCat"
+	local desktop_file="${FILESDIR}/icon/${PN}-r3.desktop"
+	local desktop_filename="${PN}.desktop"
+	local exec_command="${PN}"
+	local icon="${PN}"
+	local use_wayland="false"
+
+	if use wayland ; then
+		use_wayland="true"
+	fi
+
+	cp "${desktop_file}" "${WORKDIR}/${PN}.desktop-template" || die
+
+	sed -i \
+		-e "s:@NAME@:${app_name}:" \
+		-e "s:@EXEC@:${exec_command}:" \
+		-e "s:@ICON@:${icon}:" \
+		"${WORKDIR}/${PN}.desktop-template" \
+		|| die
+
+	newmenu "${WORKDIR}/${PN}.desktop-template" "${desktop_filename}"
+
+	rm "${WORKDIR}/${PN}.desktop-template" || die
+
+	# Install wrapper script
+	[[ -f "${ED}/usr/bin/${PN}" ]] && rm "${ED}/usr/bin/${PN}"
+	newbin "${FILESDIR}/${PN}-r1.sh" ${PN}
+
+	# Update wrapper
+	sed -i \
+		-e "s:@PREFIX@:${EPREFIX}/usr:" \
+		-e "s:@MOZ_FIVE_HOME@:${MOZILLA_FIVE_HOME}:" \
+		-e "s:@APULSELIB_DIR@:${apulselib}:" \
+		-e "s:@DEFAULT_WAYLAND@:${use_wayland}:" \
+		"${ED}/usr/bin/${PN}" \
+		|| die
+}
+
+pkg_preinst() {
+	xdg_pkg_preinst
+
+	# If the apulse libs are available in MOZILLA_FIVE_HOME then apulse
+	# does not need to be forced into the LD_LIBRARY_PATH
+	if use pulseaudio && has_version ">=media-sound/apulse-0.1.12-r4" ; then
+		einfo "APULSE found; Generating library symlinks for sound support ..."
+		local lib
+		pushd "${ED}${MOZILLA_FIVE_HOME}" &>/dev/null || die
+		for lib in ../apulse/libpulse{.so{,.0},-simple.so{,.0}} ; do
+			# A quickpkg rolled by hand will grab symlinks as part of the package,
+			# so we need to avoid creating them if they already exist.
+			if [[ ! -L ${lib##*/} ]] ; then
+				ln -s "${lib}" ${lib##*/} || die
+			fi
+		done
+		popd &>/dev/null || die
+	fi
+}
+
+pkg_postinst() {
+	xdg_pkg_postinst
+
+	elog "Cloudflare browser checks are broken with GNU IceCats anti fingerprinting measures."
+	elog "You can fix cloudflare browser checks by undoing them in about:config like below:"
+	# Specifying (X11) is necessary for it to work, even in a Wayland session
+	elog "   general.appversion.override: 91.0 (X11)"
+	elog "   general.oscpu.override: Linux x86_64"
+	elog "   general.platform.override: Linux x86_64"
+
+	if use pulseaudio && has_version ">=media-sound/apulse-0.1.12-r4" ; then
+		elog "Apulse was detected at merge time on this system and so it will always be"
+		elog "used for sound.  If you wish to use pulseaudio instead please unmerge"
+		elog "media-sound/apulse."
+		elog
+	fi
+	if [[ -n "${show_shortcut_information}" ]] ; then
+		elog
+		elog "Since ${PN}-91.0 we no longer install multiple shortcuts for"
+		elog "each supported display protocol.  Instead we will only install"
+		elog "one generic Mozilla ${PN^} shortcut."
+		elog "If you still want to be able to select between running Mozilla ${PN^}"
+		elog "on X11 or Wayland, you have to re-create these shortcuts on your own."
+	fi
+}