vszakats
commented
3 years ago Unicode support in curl is incomplete, undocumented and seemed broken in many places, so a while ago I made the decision to disable it for now. See more details in this commit. Hopefully this can be re-enabled once the support is completed and a way to help that is to address the related PRs and Issues.
(I haven't tried, but international domains can probably be used by passing them in Punycode form.)
While dependecies like openssl are compiled with
-DUNICODE, the actual curl library itself isn't. This means international domain names can't be used with these builds.