For MacOS Catalina, visit [Install mysql2 on MacOS Catalina](https://gist.github.com/fernandoaleman/12698634824f5d5c00ab57b72ee2ad52)

# Problem

Installing `mysql2` gem errors on MacOS Mojave. 

# Solution

Make sure `openssl` is installed on Mac via Homebrew.
```
brew install openssl
```

Install `mysql2` gem.
```
gem install mysql2 -v '0.5.2' -- --with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include
```