From: twalpole@... Date: 2017-01-05T20:59:26+00:00 Subject: [ruby-core:78982] [Ruby trunk Bug#13107] def_delegators causes random errors in MRI 2.4.0 Issue #13107 has been updated by Thomas Walpole. Forgot to add the location reported for the error # /home/travis/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/forwardable.rb:228:in `last_response' ---------------------------------------- Bug #13107: def_delegators causes random errors in MRI 2.4.0 https://bugs.ruby-lang.org/issues/13107#change-62397 * Author: Thomas Walpole * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: * Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN ---------------------------------------- In the Capybara project we use the rack_test gem which uses def_delegators to forward last_reponse to @rack_mock_session - https://github.com/brynary/rack-test/blob/master/lib/rack/test.rb#L29 When running the Capybara test test suite calling last_reponse on a rack_test Session object will sporadically result in a TypeError from forwardable.rb TypeError: wrong argument type Integer (expected Proc) Patching around the delegator with class Rack::Test::Session def last_response @rack_mock_session.last_response end end stops the error from occurring, so it appears that something def_delegators is doing is causing problems. Unfortunately I have not yet been able to establish exactly what causes the issues to produce a simple test case. -- https://bugs.ruby-lang.org/ Unsubscribe: