[ruby/irb] Change debug test workaround to use ENV RUBY_DEBUG_TEST_UI (https://github.com/ruby/irb/pull/1014)
https://github.com/ruby/irb/commit/9933584754
[ruby/irb] Change debug test workaround to use ENV
RUBY_DEBUG_TEST_UI
(https://github.com/ruby/irb/pull/1014)
https://github.com/ruby/irb/commit/9933584754