ruby-google-protobuf binary package in Ubuntu Focal armhf

 Protocol Buffers are Google's data interchange format.
 .
 This library contains the Ruby extension that implements Protocol Buffers
 functionality in Ruby.
 .
 The Ruby extension makes use of generated Ruby code that defines message and
 enum types in a Ruby DSL. You may write definitions in this DSL directly, but
 we recommend using protoc's Ruby generation support with .proto files. The
 build process in this directory only installs the extension; you need to
 install protoc as well to have Ruby code generation functionality.

Source package