title: How to install OS X 10.12 command line tools on 10.11?
body: <p>I get this error when trying to <code>brew install geckodriver</code></p>
  
  <pre><code>==&gt; Installing geckodriver dependency: rust
  ==&gt; Downloading https://static.rust-lang.org/dist/rustc-1.42.0-src.tar.gz
  ######################################################################## 100.0%
  ==&gt; ./configure --prefix=/usr/local/Cellar/rust/1.42.0 --release-channel=stable
  ==&gt; make
  Last 15 lines from /Users/nilshaus/Library/Logs/Homebrew/rust/02.make:
  2020-04-12 21:13:48 -0400
  
  make
  
  make: error: unable to find utility "make", not a developer tool or in PATH
  xcodebuild: error: SDK "/Library/Developer/CommandLineTools/SDKs/MacOSX10.12.sdk" cannot be located.
  clang: error: unable to find utility "clang", not a developer tool or in PATH
  
  Do not report this issue to Homebrew/brew or Homebrew/core!
  
  These open issues may also help:
  Rust dependents that currently fail to build from source https://github.com/Homebrew/homebrew-core/issues/50815
  
  Error: 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 while you are running this old version.
  </code></pre>
  
  <p>Obviously 10.11 is no longer supported by Homebrew. The fact that it can't find <code>make</code> is weird, but I'm willing to bet that the real issue is that the rust build expects the 10.12 command line tools. Is there a way for me to install them on OS X 10.11? I have Xcode 8.</p>