genroot

#!/bin/sh
set -eu

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

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

# Creates an ROOT using portage based on a package list
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, install just enough to avoid circular dependencies
extrapkg=""
test $opt_build = y && extrapkg="
    dev-lang/go
    dev-lang/rust
"
# TODO: Use `qlist -ICF '=%{CATEGORY}/%{PF}' --root "$BROOT"` to install all packages instead

# Install rest of the system
emerge --ask=n -KDU \
    --with-bdeps=$opt_build \
    --quickpkg-direct=$(test $opt_final = y && echo n || echo y) \
    @world $extrapkg

# 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