Error installing fpm:
	The last version of public_suffix (< 6.0, >= 2.0.2) to support your Ruby & RubyGems was 4.0.7. Try installing it with `gem install public_suffix -v 4.0.7` and then running the current command again
	public_suffix requires Ruby version >= 2.6. The current ruby version is 2.5.0.

Maybe a similar cause like this one: #1918

I assume this will happen more and more as direct and transitive ruby dependencies will require higher ruby versions that are only available in current Linux distributions. All the LTS distributions like Debian LTS, Ubuntu LTS, RedHat, etc. are "sensitive" to this problem. Debian 11 is not affected and i assume the latest Ubuntu and Fedora versions are not affected too.

P.S.
I think fpm is such "sensitive" because many developers must build software that dynamically links to libraries from these LTS distributions and thus the packaging build step runs on these LTS distributions as well.