For 3.0: update ruby versions supported

[jrochkind]

MRI >= 2.2, jruby >= 9.0. Drop jruby 1.7 and earlier MRI.

[jrochkind]

I noticed Nikitas Tampakis (@tampakis) said in a listserv post that they're still using JRuby 1.7 due to errors when using 9k. Those Jruby errors are mysterious to me (and all tests pass in Jruby 9k). I myself no longer use Traject at my day job.

Does anyone think it will be a problem to support only JRuby 9.0+ in traject 3.0? I'd really like to use ruby features only available in MRI 2.1+, which JRuby 9.0 is compatible with, but JRuby 1.7 is not. @billdueber

[jrochkind]

(Also failing MRI 2.5 for annoying rubygems bug interacts with travis reasons, will deal with it later if travis doesn't fix it somehow travis-ci/travis-ci#8969).

[jrochkind]

So far I have avoided writing any code that requires ruby 2.0+, because we haven't resolved this issue.

The most obvious inconvenience is being unable to use new-style keyword arguments, having to do the options = {} thing, which makes the method signatures and available keywords much less obvious in code-reading, and requires extra work if you want to throw on unrecognized (ie mis-spelled) keywors, etc. As a result, I'm often avoiding keyword arguments in places they would make things more readable if I used them.

There are other conveniences that aren't occurring to me now.

It can definitely be done, it's just kind of a pain, for a version of ruby that is well past end-of-life and no longer even receiving updates for major security vulnerabiltiies. We can do it if we need to, but I'd definitely appreciate you trying to discover a bit more about the nature of the problems you were having, before we do that. We won't drop support for any versions except on a major version release, which will be rare, so the 3.0 release I'm working on now would be a great time to drop some of this cruft.

[jrochkind]

@tampakis have you had a chance to see if recent jruby 9k releases still give you problems, or learn anything more about your problems?

It looks like JRuby 1.7 is offiically out-of-support as of November. jruby/jruby#4112 (comment)

[jrochkind]

Gah, running locally on ruby 2.5.0, the test suite actually produces an interpreter crash with a core dump. /Users/jrochkind/.gem/ruby/2.5.0/gems/marc-1.0.2/lib/marc/xml_parsers.rb:179: [BUG] Stack consistency error (sp: 146, bp: -566524928).

Trying to investigate what's going on.

Looks like there may be a bug in REXML in MRI 2.5.0. How annoying. Difficult to reproduce to a test case that I can report to ruby, but trying.

[jrochkind]

Error in MRI 2.5 seems to be an actual bug in MRI 2.5 that causes a crash and core dump.

ruby-marc in REXML mode triggers it, reported at ruby-marc/ruby-marc#53

Narrowed down to a reproduction without ruby-marc involved, reported to ruby at: https://bugs.ruby-lang.org/issues/14403

[tampakis]

@jrochkind we have updated our indexing routine to use MRI so we won't need 1.7 support anymore.

[jrochkind]

ok, thanks for the update @tampakis!

Did you find much slowdown with MRI?