Hi all haskell lovers

I'm trying to print out Double in russian locale (we use "," as decimal separator insetad of "."). I'm trying to set locale with System.Locale.SetLocale like

setLocale LC_ALL $ Just "ru_RU.UTF-8"

this returns Just "ru_RU.UTF-8", so it seems that function call succeeded, but when I call 

show 20.2

it just prints 20.2 and not desired 20,2

Can anyone please help?