With ruby 3.3.5 some gems are extracted from standard library. Therefore we get warning to migrate them into gemfile/gemspec.
You can add ostruct to your Gemfile or gemspec to silence this warning.
Also please contact the author of ffi-rzmq-2.0.7 to request adding ostruct into its gemspec.
With ruby
3.3.5
some gems are extracted from standard library. Therefore we get warning to migrate them into gemfile/gemspec.PR to fix the issue: https://github.com/chuckremes/ffi-rzmq/issues/135