This is a very common issue where we get error “Error installing mysql2: Failed to build gem native extension” while installing mysql2 gem in Rails(in Ubuntu Linux OS). The problem is due to missing libmysql(from MYSQL) file.
To solve the issue install the compnents libmysql-ruby and libmysqlclient-dev using the command sudo apt-get install libmysql-ruby libmysqlclient-dev (Run in Ubuntu Terminal). Then run gem install mysql2 which should run successfully.
Run the following command where we pass the location of MYSQL lib and include folder. Replace the PATH with the actual location of MYSQL Server application.
gem install mysql2 — ‘–with-mysql-lib=”PATH\MySQL Server 5.5\lib” –with-mysql-include=”PATH\MySQL Server 5.5\include”‘