#!/usr/bin/env bash
set -euo pipefail
unset MAKEFLAGS MFLAGS GNUMAKEFLAGS
make_bin=$(command -v gmake || command -v make)
m() { "$make_bin" --no-print-directory -rR "$@"; }
work_dir=$(mktemp -d)
if [ "${KEEP_WORK:-0}" = 1 ]; then
  trap 'printf "Artifacts: %s\n" "$work_dir"' EXIT
else
  trap 'rm -rf -- "$work_dir"' EXIT
fi
cd "$work_dir"
export TMPDIR="$work_dir"
cat > extra.mk <<'INPUT_58_1'
WORDS += extra
INPUT_58_1
cat > Makefile <<'MAKEFILE'
WORDS := base
all:
	@printf "%s\n" "$(WORDS)"
MAKEFILE
mv Makefile base.mk
m -s -f base.mk -f extra.mk all