undefined method `transform_keys' loading Sidekiq web

Question

After updating gems, it does not load the sidekiq website giving the following error:

NoMethodError (undefined method `transform_keys' for <ActionDispatch::Request::Session:0x00005568df2a8710>):

The gems that were updated were:

selenium-webdriver 3.142.7
rack-protection 2.0.8.1
mime-types 3.3.1
 mini_magick 4.10.1
image_processing 1.10.3
groupdate 4.3.0
friendly_id 5.3.0
faraday 0.17.3
http 4.3.0
public_suffix 4.0.3
rack 2.1.1
crass 1.0.6
i18n 1.7.1
minitest 5.14.0

ruby version: ruby 2.6.0p0 (2018-12-25 revision 66547) [x86_64-linux]

Full error message

Answer 1

It seems to be an issue with Rack 2.1.1. It works ok with 2.0.8.

Answer 2

it's a rack issue and fixed by this PR: https://github.com/rack/rack/pull/1428