libzmq missing

[MatzFan]

On Debian 12 (bookworm) I tried to run the tests with bundle exec rake and got:

An error occurred while loading ./spec/lib/protobuf/rpc/connectors/ping_spec.rb. - Did you mean?
                    rspec ./spec/lib/protobuf/rpc/connectors/zmq_spec.rb
                    rspec ./spec/lib/protobuf/rpc/connectors/socket_spec.rb
                    rspec ./spec/lib/protobuf/rpc/connectors/base_spec.rb

Failure/Error: require 'ffi-rzmq'

LoadError:
  The libzmq library (or DLL) could not be loaded

Tried again after sudo apt install libzmq3-dev and tests were green :-).

Thought I'd report it as I expect the library should be checked for somewhere when the gem is installed.