How do I get rid of these notifications when I run a Ruby file

console.txt

$ ruby test.rb 
Ignoring eventmachine-1.0.3 because its extensions are not built.  Try: gem pristine eventmachine --version 1.0.3
Ignoring executable-hooks-1.3.1 because its extensions are not built.  Try: gem pristine executable-hooks --version 1.3.1
Ignoring faye-websocket-0.4.7 because its extensions are not built.  Try: gem pristine faye-websocket --version 0.4.7
Ignoring ffi-1.9.0 because its extensions are not built.  Try: gem pristine ffi --version 1.9.0
Ignoring gem-wrappers-1.2.4 because its extensions are not built.  Try: gem pristine gem-wrappers --version 1.2.4
Ignoring gherkin-2.12.1 because its extensions are not built.  Try: gem pristine gherkin --version 2.12.1
Ignoring gherkin-2.12.0 because its extensions are not built.  Try: gem pristine gherkin --version 2.12.0
Ignoring hiredis-0.4.5 because its extensions are not built.  Try: gem pristine hiredis --version 0.4.5
Ignoring http_parser.rb-0.5.3 because its extensions are not built.  Try: gem pristine http_parser.rb --version 0.5.3
Ignoring json-1.8.0 because its extensions are not built.  Try: gem pristine json --version 1.8.0
Ignoring json-1.7.6 because its extensions are not built.  Try: gem pristine json --version 1.7.6
Ignoring json-1.7.0 because its extensions are not built.  Try: gem pristine json --version 1.7.0
Ignoring nokogiri-1.6.1 because its extensions are not built.  Try: gem pristine nokogiri --version 1.6.1
Ignoring nokogiri-1.6.0 because its extensions are not built.  Try: gem pristine nokogiri --version 1.6.0
Ignoring pg-0.17.1 because its extensions are not built.  Try: gem pristine pg --version 0.17.1
Ignoring pg-0.17.0 because its extensions are not built.  Try: gem pristine pg --version 0.17.0
Ignoring pg-0.16.0 because its extensions are not built.  Try: gem pristine pg --version 0.16.0
Ignoring pg-0.12.2 because its extensions are not built.  Try: gem pristine pg --version 0.12.2
Ignoring redcarpet-3.2.2 because its extensions are not built.  Try: gem pristine redcarpet --version 3.2.2
Ignoring sqlite3-1.3.9 because its extensions are not built.  Try: gem pristine sqlite3 --version 1.3.9
Ignoring sqlite3-1.3.8 because its extensions are not built.  Try: gem pristine sqlite3 --version 1.3.8
Ignoring sqlite3-1.3.7 because its extensions are not built.  Try: gem pristine sqlite3 --version 1.3.7
Ignoring sqlite3-1.3.6 because its extensions are not built.  Try: gem pristine sqlite3 --version 1.3.6
Ignoring therubyracer-0.12.1 because its extensions are not built.  Try: gem pristine therubyracer --version 0.12.1
Ignoring thin-1.5.1 because its extensions are not built.  Try: gem pristine thin --version 1.5.1

gem pristine eventmachine --version 1.0.3
gem pristine executable-hooks --version 1.3.1
gem pristine faye-websocket --version 0.4.7
gem pristine ffi --version 1.9.0
gem pristine gem-wrappers --version 1.2.4
gem pristine gherkin --version 2.12.1
gem pristine gherkin --version 2.12.0
gem pristine hiredis --version 0.4.5
gem pristine http_parser.rb --version 0.5.3
gem pristine json --version 1.8.0
gem pristine json --version 1.7.6
gem pristine json --version 1.7.0
gem pristine nokogiri --version 1.6.1
gem pristine nokogiri --version 1.6.0
gem pristine pg --version 0.17.1
gem pristine pg --version 0.17.0
gem pristine pg --version 0.16.0
gem pristine pg --version 0.12.2
gem pristine redcarpet --version 3.2.2
gem pristine sqlite3 --version 1.3.9
gem pristine sqlite3 --version 1.3.8
gem pristine sqlite3 --version 1.3.7
gem pristine sqlite3 --version 1.3.6
gem pristine therubyracer --version 0.12.1
gem pristine thin --version 1.5.1