ruby on rails error for databases

Question

I am new to ror when i try to bundle install below error is showing when i use mysql2 instead of sqllite same error

i am using linux hosting and site shows internal server error as per my little knowledge server is using phussion passenger

Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

        /opt/ruby/bin/ruby extconf.rb
checking for sqlite3.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/opt/ruby/bin/ruby
        --with-sqlite3-dir
        --without-sqlite3-dir
        --with-sqlite3-include
        --without-sqlite3-include=${sqlite3-dir}/include
        --with-sqlite3-lib
        --without-sqlite3-lib=${sqlite3-dir}/lib
/opt/ruby/lib/ruby/1.9.1/mkmf.rb:381:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
        from /opt/ruby/lib/ruby/1.9.1/mkmf.rb:506:in `try_cpp'
        from /opt/ruby/lib/ruby/1.9.1/mkmf.rb:970:in `block in find_header'
        from /opt/ruby/lib/ruby/1.9.1/mkmf.rb:790:in `block in checking_for'
        from /opt/ruby/lib/ruby/1.9.1/mkmf.rb:284:in `block (2 levels) in postpone'
        from /opt/ruby/lib/ruby/1.9.1/mkmf.rb:254:in `open'
        from /opt/ruby/lib/ruby/1.9.1/mkmf.rb:284:in `block in postpone'
        from /opt/ruby/lib/ruby/1.9.1/mkmf.rb:254:in `open'
        from /opt/ruby/lib/ruby/1.9.1/mkmf.rb:280:in `postpone'
        from /opt/ruby/lib/ruby/1.9.1/mkmf.rb:789:in `checking_for'
        from /opt/ruby/lib/ruby/1.9.1/mkmf.rb:969:in `find_header'
        from extconf.rb:30:in `<main>'


Gem files will remain installed in /home/jformmp7/ruby/gems/gems/sqlite3-1.3.10 for inspection.
Results logged to /home/jformmp7/ruby/gems/gems/sqlite3-1.3.10/ext/sqlite3/gem_make.out
An error occurred while installing sqlite3 (1.3.10), and Bundler cannot
continue.
Make sure that `gem install sqlite3 -v '1.3.10'` succeeds before bundling.

contents of gemfile

source 'https://rubygems.org'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.1.6'
# Use sqlite3 as the database for Active Record
#gem 'sqlite3'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 4.0.3'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .js.coffee assets and views
gem 'coffee-rails', '~> 4.0.0'
# See https://github.com/sstephenson/execjs#readme for more supported runtimes
gem 'therubyracer',  platforms: :ruby
#gem "therubyracer"
# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
gem 'turbolinks'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', '~> 0.4.0',          group: :doc

# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring',        group: :development

# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use unicorn as the app server
# gem 'unicorn'

# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development

# Use debugger
# gem 'debugger', group: [:development, :test]

#gem 'mysql2'

Answer 1

I guess you are on ubuntu?

Happened to me in the past, hopefuly it will be resolved by typing.

sudo apt-get install sqlite3 libsqlite3-dev
bundle install