If in Debian-Based type:
apt-get install libsqlite3-dev
and so:
gem install sqlite3-ruby
you see this message:
Building native extensions. This could take a while…
Successfully installed sqlite3-ruby-1.2.4
1 gem installed
Installing ri documentation for sqlite3-ruby-1.2.4…
Installing RDoc documentation for sqlite3-ruby-1.2.4…
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