Can't install mysql2 gem on macOS Sierra

Question

I\'m setting up my development environment in the new macOS Sierra .

First of all, I installed Rbenv, Ruby (2.3.1)

Answer 1

Here's what worked for me.

Originally I ran:

$ bundle config --local build.mysql2 "--with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include"

then

$ bundle install

I received an error in /Users/.../.bundle/ruby/2.5.0/extensions/x86_64-darwin-18/2.5.0/mysql2-0.5.3/mkmf.log :

clang: error: unsupported option '--with-cppflags=-I/usr/local/opt/openssl/include'

So I removed "--with-cppflags=-I/usr/local/opt/openssl/include"

Then ran:

$ bundle config --local build.mysql2 "--with-ldflags=-L/usr/local/opt/openssl/lib"

followed by:

$ bundle install

Which worked.