Add instructions for installing Ruby 2 on Mac OS X with homebrew

README.md

@@ -92,6 +92,18 @@ To see a list of all available Ruby versions, run `ruby-build
 Pass the `-v` or `--verbose` flag to `ruby-build` as the first
 argument to see what's happening under the hood.
 
+Ruby 2 is incompatible with the version of OpenSSL bundled with Mac OS X, so it
+doesn't compile the extension.
+
+To work around this issue, install OpenSSL using homebrew instead:
+
+    brew install openssl
+
+Then set the CONFIGURE_OPTS environment variable when you build Ruby:
+
+    export CONFIGURE_OPTS="--with-openssl-dir=`brew --prefix openssl`"
+    rbenv install 2.0.0-preview1
+
 ### Custom definitions
 
 Both `rbenv install` and `ruby-build` accept a path to a custom