$ gem install oj -- --enable-trace-log

To enable Oj trace feature, it uses --enable-trace-log option when installing the gem. Then, the trace logs will be displayed when :trace option is set to true.

$ gem install oj -- --with-sse42

To enable the use of SIMD instructions in Oj, it uses the --with-sse42 option when installing the gem. This will enable the use of the SSE4.2 instructions in the internal.