Ruby tests have been failing for quite some time, here's my fix.
From 2f1bbaab939f6b6ceceb72862470e0576a8e2cba Mon Sep 17 00:00:00 2001
From: Achim Gratz <Stromeko@Stromeko.DE>
Date: Sun, 12 May 2019 13:14:04 +0200
Subject: [PATCH 1/1] test-ob-ruby.el: fix tests
* testing/lisp/test-ob-ruby.el: Output no longer contains a trailing
newline, remove from the template to compare against. Session must
be named for the tests to actually work, also add some extra code to
ascertain that the code after the output statement has actually run
in the session.
* lisp/ob-ruby.el (org-babel-ruby-evaluate): Clean up the session code
and remove a superfluous `butlast'. Work around a problem in comint
where the first prompt in a session may be printed after the
evaluation has already started, thus producing a spurious line in
the output.
* testing/lisp/test-ob-ruby.el (test-ob-ruby/session-output-1,
test-ob-ruby/session-output-2 test-ob-ruby/session-output-3): Test
correct transfer of interpreter state across several session
invocations.
* lisp/ob-ruby.el (org-babel-ruby-evaluate): Temporarily disable the
irb prompt to ensure that the output is properly recognized using
the standard settings from inf-ruby and no extra settings in .irbrc
or other configuration files from Ruby. Remove superfluous
`comint-send-input' that produced a spurious empty line in output.
* testing/lisp/test-ob-ruby.el (test-ob-ruby/session-output): Remove
spurious emtpy line in expected output.
* lisp/ob-ruby.el (org-babel-ruby-evaluate):
set conf.echo=false for the duration of evaluation.
* testing/lisp/test-ob-ruby.el (test-ob-ruby/session-output): new test.