我正在更新我的 mac 上的一些程序，突然在运行 gnuplot 时遇到了一些麻烦。错误是这样的：
dyld: Library not loaded: /usr/local/opt/readline/lib/libreadline.7.dylib
Referenced from: .../something/...
Reason: image not found
Trace/BPT trap: 5
这不是我自己的错误（我从互联网上复制粘贴了这个非常接近的错误），因为从那时起我卸载了 gnuplot 并且无法再安装它。
当我运行时brew install gnuplot，我得到：
Warning: You are using macOS 10.11.
We (and Apple) do not provide support for this old version.
You will encounter build failures with some formulae.
Please create pull requests instead of asking for help on Homebrew's GitHub,
Discourse, Twitter or IRC. You are responsible for resolving any issues you experience, as you …