Re: [PATCH] Update ruby_version requirement to allow ruby 3.0

[Jean Boussier <jean.boussier@shopify.com>]

> Perhaps adding warnings about untested+unsupported
> versions to test_helper.rb and extconf.rb is a better way to go?

That could work yes. Something akin to:
"This ruby version wasn't tested, blah blah".

> Then, maybe leave the version check out of the gemspec entirely.

The gemspec ruby version is very useful but for minimum requirement
only. e.g. `>= 1.9.3`.

> Fwiw, the type of breakage from incompatibilities I'm worried
> about is subtle things that don't show up immediately
> (e.g. encodings, hash ordering, frozen strings, etc...).

That's understandable, but 3.0 is not any more likely that 2.7
to break any of these, and it's important that gems are testable on
ruby pre-release, otherwise you end up with a chicken and egg
problem of not being able to report compatibility breakages
to ruby-core.

On a totally different note, it seems that unicorn is not compiling
quite properly against Ruby 3.0.0-dev, at least on linux:

   unicorn_http.so: undefined symbol: Init_unicorn_http

I'm trying to figure out why the symbol isn't exported,
I might come back with another patch. But just in case
you might have an idea what's going on.