/usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require': cannot load such file -- fastimage (LoadError)

[luckysunda]

I have tried to run calamari for python 3 and tesseract but getting the above error.
For calamari I am using this command:

ruby ./lib/ocr.rb calamari ../../Pictures/test/test.png

What am I doing wrong here?