eval "$(
  declare -f build | \
    sed '
      /.*make.*$_buildopts/ i \
        _buildopts="${_buildopts/MARCH=x86-64/MARCH=pentium4}" \
    '
)"

eval "$(
  declare -f package | \
    sed '
      /.*make.*$_buildopts/ i \
        _buildopts="${_buildopts/MARCH=x86-64/MARCH=pentium4}" \
    '
)"

eval "$(
  declare -f build | \
    sed '
      /^\s*make / i export CFLAGS+=" -march=pentium4" \
                    export CXXFLAGS+=" -march=pentium4"
    '
)"

eval "$(
  declare -f package | \
    sed '
      /^\s*make / i export CFLAGS+=" -march=pentium4" \
                    export CXXFLAGS+=" -march=pentium4"
    '
)"