m4 在 mac 下 Abort trap: 6的解决

参考homebrew下的m4安装描述，https://github.com/Homebrew/homebrew-core/blob/master/Formula/m4.rb

 # Fix crash from usage of %n in dynamic format strings on High Sierra
  # Patch credit to Jeremy Huddleston Sequoia <jeremyhu@apple.com>
  if MacOS.version >= :high_sierra
    patch :p0 do
      url "https://raw.githubusercontent.com/macports/macports-ports/edf0ee1e2cf/devel/m4/files/secure_snprintf.patch"
      sha256 "57f972940a10d448efbd3d5ba46e65979ae4eea93681a85e1d998060b356e0d2"
    end
end

手动打上面的补丁，编译安装。