1. Procedure of installing Jekyll in Mac OS X

  2. Install Xcode Command line tools: http://stackoverflow.com/questions/9329243/xcode-4-4-and-later-install-command-line-tools

  3. Clang error during install Jekyll

clang: error: unknown argument: '-multiply_definedsuppress' [-Wunused-command-line-argument-hard-error-in-future]
clang: note: this will be a hard error (cannot be downgraded to a warning) in the future
make: *** [redcarpet.bundle] Error 1

make failed, exit code 2

Solution:

export ARCHFLAGS="-Wno-error=unused-command-line-argument-hard-error-in-future"
export CFLAGS=-Wunused-command-line-argument-hard-error-in-future
export CPPFLAGS=-Qunused-arguments
sudo -E gem install jekyll
References: