Custom locales seem not to work

[Алекса -скрыто-]

> I have never seen ie used as a language code under Linux systems, and it 
> is interlingual, associated with unspecified territory code XX, so you 
> would have to set each locale category separately to achieve the desired 
> effects: fr_CH or en_US.

... the locale should be set to "ie_XX.UTF-8", which the locale data provides, not "C" like Cygwin does now.