genroot

#!/bin/sh
set -eu

opt_build="${build:-n}"
unset build
opt_final="${final:-n}"
unset final

# Allow setting parallelization level of portage... not recommended.
NPROC="${NPROC:-1}"

BROOT="$(portageq envvar BROOT)"
export ROOT="${1:-$PWD/root}"
test $opt_build = y && ROOT="${1:-$PWD/broot}"

export EMERGE_LOG_DIR="$ROOT/var/log"
export PORTAGE_LOGDIR="$ROOT/var/log/portage"
export PORTAGE_TMPDIR="$ROOT/var/tmp"
export FEATURES='-news -parallel-fetch'
export QUICKPKG_DEFAULT_OPTS='--include-config=y'  # for --quickpkg-direct=y

# silence linux-info.eclass warnings
export CHECKCONFIG_DONOTHING=y
export SKIP_KERNEL_CHECK=y

# Create ROOT directory with the correct permissions
install -dm00755 -g"$(id -g)" "$ROOT"

# Populate it with a package list from BROOT
mkdir -p "$PORTAGE_TMPDIR" "$EMERGE_LOG_DIR"
install -v -Dm644 -t "$ROOT/var/lib/portage" \
    "$BROOT/var/lib/portage/world" "$BROOT/var/lib/portage/world_sets"

# Create base filesystem
test -d "$ROOT/var/db/pkg" && qlist -Ie sys-apps/baselayout > /dev/null || \
    USE=build \
    emerge --ask=n -nU \
        sys-apps/baselayout

# HACK: Set PKGDIR to a nonsense value to avoid using local binpkgs (as it may ignore package.provided)
test $opt_final = y || export PKGDIR=/dev/null

# Install all DEPENDs in a broot
test $opt_build = y && export SYSROOT="$ROOT"

# I have no idea how to install all BDEPENDs
# So instead, pass a full list of packages...
pkg="@world"
test $opt_build = y && pkg="$(qlist -ICF '=%{CATEGORY}/%{PF}' --root "$BROOT/")"

# Sometimes, the running system might have packages that pull old deps,
# causing the installation of all packages to fail.
# Sus them out with the following command:
#   emerge --root /tmp/root --quickpkg-direct=y --tree -pk $(qlist -ICF '=%{CATEGORY}/%{PF}') | tee log; less log
# Look for packages that depend on things that can't be installed as binpkg
# Rebuild those packages with:
#   emerge -1 --changed-deps --binpkg-changed-deps <pkg>

# Install rest of the system
emerge --ask=n -1KDN -j "$NPROC" \
    --exclude 'sys-kernel/gentoo-kernel:6.6.13' \
    --quickpkg-direct=$(test $opt_final = y && echo n || echo y) \
    $pkg

# Work around bad vim-related symlinks
# https://bugs.gentoo.org/922614
for x in "$ROOT/usr/share/vim"/vim*/doc/*.txt; do
    test -h "$x" || continue
    link="$(readlink "$x")"
    case "$link" in
        "$ROOT/usr/share/vim/vimfiles/doc"/*.txt)
            ln -sfvrT "$link" "$x"
            ;;
    esac
done