Crystal: File.dirname is broken for directories ending with a non-latin letter

[sudo-nice]

This code:

%w[
  /τελεία/τελεία
  /Månedå/Månedå
].each { |dir| pp File.dirname dir }

produces

"/τελεί\xCE"
"/Måned\xC3"

https://carc.in/#/r/8q5k

---

Crystal 0.33.0 [612825a53] (2020-02-14)

LLVM: 8.0.0
Default target: x86_64-unknown-linux-gnu

[Sija]

Stopped working in Crystal 0.28.0 (using the new impl. based on Path#dirname).

[asterite]

On it.