- Removal of the class setters, such as
Rack::Timeout.timeout = 5, may lead to an error when upgrading. To fix this, remove these setters and instead use either the environment variables,RACK_TIMEOUT_*, or insert the middleware manually and configure the middleware as desired when inserting.
- The Rollbar support was removed; a deprecation warning will be emitted if you are using this module. The recommendation is to use Rollbar's custom fingerprinting. A recommendation is provided in doc/rollbar.md.