TravisCI: removed Ruby versions < 2.3 since rubygems deprecated them

[alessio-signorini]

$ gem update --system
Updating rubygems-update
Fetching: rubygems-update-3.0.1.gem (100%)
ERROR:  Error installing rubygems-update:
	rubygems-update requires Ruby version >= 2.3.0.
ERROR:  While executing gem ... (NoMethodError)
    undefined method `version' for nil:NilClass

[rafaelfranca]

Where can I read more about this removal? Thor still support Ruby < 2.3 so we need to test on them in some way

[alessio-signorini]

@rafaelfranca, the log I attached above is the output of gem update --system.

Rubygems v3.0+ require Ruby >= 2.3. Here is a link to the issue on their Github.

Ruby 2.3 was released in 2015.

[rafaelfranca]

Right. An easier fix is to change the gem update --system call on travis to define a version that is not rubygems 3.0 for rubies < 2.3.

[alessio-signorini]

@rafaelfranca that's an idea. I looked at this link but could not find an easy way to do it. Do you know how? Do you mind creating a PR for that? How do we know the Ruby versions that need to be supported by Thor?

[piotrmurach]

As far as I understand each ruby installation includes a version of rubygems. Even the latest Ruby v2.6.0 isn't released with rubygems v3.0. Therefore this is an issue for future releases of Ruby. Therefore I would be inclined to remove gem update --system from the travis config file all together. I would also constraint gem install bundler to version < 2.0.0 due to imcompatibility with rubies < 2.3.0.

[deivid-rodriguez]

Maybe we can actually drop support instead. Thor's main dependants, Rails and Bundler, have already moved on, so maybe it's time?

[piotrmurach]

@deivid-rodriguez That sounds like a drastic step. I do use thor in my project called tty and I'm keen for this library to support Ruby >= 2.0.0. I belive there is value in maintaining older versions of Ruby and progressively eliminating more defunct ones. For example, dropping 1.8.7 support could be a good first step?

[deivid-rodriguez]

My take to this is to follow the upstream policy, so when ruby-core drops support for a version of ruby, I drop support too. But this is up to the maintainers to decide :)

[rafaelfranca]

I'm up to remove support of older version on thor 1.0 but right now I'd prefer a green build in all the versions we support today.

[deivid-rodriguez]

So that means that the next version will not yet be 1.0, or at least that you haven't yet decided it... Right?

[deivid-rodriguez]

What about for dropping support for rubies under 2.0, @rafaelfranca? Would you be willing to merge that now if I open a PR?