I18n.locale = --> setting this is ignored

gistfile1.txt

From: /home/rca/work/code/ror/leihs/app/controllers/application_controller.rb @ line 72 ApplicationController#set_gettext_locale:

    67:     end
    68:     
    69:     I18n.locale = locale_symbol
    70:     FastGettext.locale = locale_symbol.to_s
    71: 
 => 72:     binding.pry
    73: 
    74:   end
    75: 
    76: end

[1] pry(#<Backend::InventoryPoolsController>)> I18n.locale
=> :es
[2] pry(#<Backend::InventoryPoolsController>)> FastGettext.locale
=> "es"
[3] pry(#<Backend::InventoryPoolsController>)> locale_symbol
=> :"en-GB"
[4] pry(#<Backend::InventoryPoolsController>)> locale_symbol.to_s
=> "en-GB"
[5] pry(#<Backend::InventoryPoolsController>)> I18n.locale = :"en-GB"
=> :"en-GB"
[6] pry(#<Backend::InventoryPoolsController>)> I18n.locale
=> :es