Error Message "Xcode alone is not sufficient on Sierra"
command-line-tool, homebrew, python-3.x, ruby, xcode
Solution
Let me explain this myself so people won't make the same mistakes.
When I saw the last line of the error message
Error: Xcode alone is not sufficient on Sierra.
Install the Command Line Tools:
xcode-select --install
My thought was: I already have Xcode why the system ask me to "reinstall" it. However, thanks for @SamiKuhmonen @ Beartech @patrick kuang suggestion, I search a page (in Mandarin). `xcode-select --install` does not reinstall the whole Xcode. It means install some missing command line tools which is required by installing Ruby.
Problem
I'd like to install openCV to vectorize image, but there's a series error message regarding Xcode and Ruby. First, I use terminal to install openCV, `brew install opencv`. Then, I got error message indicating that the system doesn't like my ruby version. ``` /usr/local/Homebrew/Library/Homebrew/brew.rb:12:in `<main>': Homebrew must be run under Ruby 2.3! You're running 2.0.0. (RuntimeError) ``` So, I want to upgrade my ruby. I followed several update strategy from this post. First ruby upgrade trial: `brew link --overwrite ruby` & `brew unlink ruby && brew link ruby` and get ``` Error: No such keg: /usr/local/Cellar/ruby ``` Then second ruby upgrade trial: `brew upgrade ruby` and see the following error message. ``` Error: Xcode alone is not sufficient on Sierra. Install the Command Line Tools: xcode-select --install ``` This error message means I need to install Xcode which I already install. So, I check my Xcode status with `code-select -p` and get `/Applications/Xcode.app/Contents/Developer` which means I am fine. I saw a comment regarding where you install python could be a big issue. Quote from the source: If you see `/usr/local/bin/python3` then you are correctly using the Homebrew version of Python. If the output is instead `/usr/bin/python3` then you are incorrectly using the system version of Python. I check `which python3` and get ``` /Users/******/anaconda3/bin/python3 ``` Could this be the problem? How can I change system version to local?