There are errors like the following when installing Ruby gems using OpenSSL in OSX 10.11:
mini_ssl.c:4:10: fatal error: 'openssl/bio.h' file not found
Since OpenSSL is not included in OSX 10.11, we have to install OpenSSL manually. I have already installed it with Homebrew:
brew install openssl
There are many ways to fix the problem, the approach I decided to take is adding build flags to Bundler configuration.
For example, the following command tells Bundler that for the
puma gem, I want to use the OpenSSL installation from Homebrew:
bundle config build.puma --with-cppflags=-I$(brew --prefix openssl)/include