Install Firefox from Gentoo binpkg

Unfortunately, even building Firefox with GCC fails:

> 3:30.02 [gecko-profiler 0.1.0] /../lib/gcc/aarch64-unknown-linux-gnu/14/include/g++-v14/cstdlib:79:15: fatal error: 'stdlib.h' file not found
> 3:30.02 [gecko-profiler 0.1.0] thread 'main' panicked at tools/profiler/rust-api/build.rs:104:10:
> 3:30.02 [gecko-profiler 0.1.0] Unable to generate bindings: ClangDiagnostic("/../lib/gcc/aarch64-unknown-linux-gnu/14/include/g++-v14/cstdlib:79:15: fatal error: 'stdlib.h' file not found\n")

Clearly, something is misconfigured, because `stdlib.h` does indeed
exist.  I am not sure what, though, and I am getting tired of messing
with this.

Fortunately, the official Gentoo binary package project has a build of
_www-client/firefox_ for ARM64.  It has a rather different USE flag
configuration than what we did, though, so we have to pull in quite a
few more dependencies.

We can't just add _www-client/firefox_ to `install.packages` because
Aimee OS runs `emerge` with `--getbinpkgonly`, which implies
`--binpkg-changed-deps=y`.  This since we want to build everything
_except_ Firefox locally, the dependency graph is quite a bit different,
so Portage ignores the binary package and will try to build
_www-client/firefox_ from source.

To work around this limitation, we need to install Firefox manually in
the `customize.sh` script in two phases.  First, we install all of its
dependencies in the build root (`/usr/aarch64-…`), but not Firefox
itself, to get binpkgs for them.  Then, we install _www-client/firefox_
in the target root (`/mnt/gentoo`) with the `--getbinpkg` and
`--usepkgonly` flags.

Hopefully, one day I can figure out how to cross-compile Firefox (and it
doesn't take days to build once I do), and we can remove this hackery.

build.packages

@@ -1,2 +1,5 @@
 sys-boot/raspberrypi-firmware
 sys-boot/u-boot
+x11-libs/gtk+
+media-libs/mesa
+media-video/ffmpeg

customize.sh

@@ -1,6 +1,18 @@
 #!/bin/sh
 # vim: set sw=4 ts=4 sts=4 et :
 
+. "${CONFIGDIR:=${PWD}}"/config
+
+O=$1
+
+export PORTAGE_CONFIGROOT="$O"/portage
+
+if [ ! -f /mnt/gentoo/usr/lib64/firefox/firefox ]; then
+    ${target}-emerge -vbknuUDj --onlydeps --with-bdeps=n www-client/firefox:esr
+    PORTAGE_BINHOST=https://distfiles.gentoo.org/releases/arm64/binpackages/23.0/arm64 \
+    ${target}-emerge -vgKnj --root=/mnt/gentoo www-client/firefox:esr
+fi
+
 passwd -R /mnt/gentoo -d root
 
 systemctl --root=/mnt/gentoo enable wpa_supplicant@wlan0

install.packages

@@ -1,2 +1,2 @@
 net-wireless/wpa_supplicant
-www-client/firefox
+media-video/pipewire

portage/make.conf/wayland.conf

@@ -1 +1 @@
-USE="${USE} -X wayland"
+USE="${USE} wayland"

portage/package.accept_keywords/firefox

@@ -1 +0,0 @@
-dev-libs/nss ~amd64

portage/package.use/firefox

@@ -2,5 +2,14 @@ media-libs/harfbuzz -cairo
 media-libs/libvpx postproc
 media-libs/mesa -llvm wayland
 media-video/ffmpeg openssl -gnutls
-www-client/firefox -clang -telemetry dbus wayland
+
+# Must match USE flags of the www-client/firefox package on the
+# offical Gentoo binhost
+www-client/firefox X clang dbus gmp-autoupdate gnome-shell jumbo-build pulseaudio system-av1 system-harfbuzz system-icu system-jpeg system-libevent system-libvpx system-webp telemetry wayland LLVM_SLOT: 19 -17 -18
+x11-libs/cairo X
 x11-libs/gtk+ wayland
+media-libs/libglvnd X
+
+# Firefox requires a PulseAudio-compatible sound server; we use Pipewire
+media-video/pipewire sound-server
+media-libs/libcanberra udev alsa

prepare.sh

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+. "${CONFIGDIR:=${PWD}}"/config
+
 if [ ! -f /var/db/repos/gentoo/metadata/timestamp ]; then
     emerge-webrsync
 fi
@@ -9,6 +11,7 @@ fi
 
 mkdir -p /etc/portage/package.use
 mkdir -p /etc/portage/make.conf
+echo 'virtual/libudev systemd' >> /etc/portage/package.use/systemd
 cp portage/package.use/firefox /etc/portage/package.use/
 cp portage/make.conf/introspection.conf /etc/portage/make.conf/
 cp portage/make.conf/wayland.conf /etc/portage/make.conf/
@@ -17,3 +20,5 @@ echo 'VIDEO_CARDS=""' > /etc/portage/make.conf/videocards.conf
 xargs -r emerge -vbknuUj --rebuilt-binaries=y --color=y <<EOF
 dev-libs/nss
 EOF
+
+[ -d /etc/portage/gnupg ] || getuto -v