Y26-018 - As a developer (Steve) I would like to upgrade to Ruby 4 to ensure the application is on an up to date version and does not accrue technical debt

[stevieing]

Describe the Housekeeping
As a developer (Steve) I would like to upgrade to Ruby 4 to ensure the application is on an up to date version and does not accrue technical debt

Blocking issues
Describe any other issues or tickets that may be blocking this change.

Additional context
Add any other context about the problem here.

[dasunpubudumal]

Situation as of 19/01/2025

• mail gem, which is part of Rails' ActionMailer is not compatible with Ruby v4 just yet. It is using a gem net-imap underneath which hasn't been upgraded to Ruby v4 so it transitively is not compatible with Ruby 4.
• We figured that out with the following stack trace:

Jan 19 11:13:49 trac-uat traction-service_puma.service[2500213]: [2500213] /var/www/traction-service/shared/vendor/bundle/ruby/4.0.0/gems/net-imap-0.5.10/lib/net/imap/config/attr_type_coercion.rb:32:in 'Ractor.make_shareable'