The real fix will happen when Data.Text moves from UTF-16 to UTF-8:

https://discourse.haskell.org/t/hf-tech-proposal-1-utf-8-enc...

Fortunately this proposal has been accepted, but I don't know the timeline for its implementation in GHC.

Until then, working with UTF-8 is kind of convoluted

https://serokell.io/blog/haskell-with-utf8

Also: libraries need to be fixed to accept Data.Text instead of String. IsString helps (it's a typeclass that contains all string types) but only if APIs take it instead of defaulting to String. Adding random string conversions to cope with legacy APIs is very annoying.