According to this problem that I've encountered today: Locale not setting on Debian
I have solved my problem by running
sudo apt-get install locales-all.
But one question - what is
sudo dpkg-reconfigure locales actually doing? Somebody said (somewhere else on the internet), that it is generating chosen locales. But for me - it wasn't doing anything. The locales were nowhere to be found on the system, thus those lines were popping up:
locale: Cannot set LC_CTYPE to default locale: No such file or directory locale: Cannot set LC_MESSAGES to default locale: No such file or directory locale: Cannot set LC_COLLATE to default locale: No such file or directory
After running the command once again (
sudo dpkg-reconfigure locales) - after installing them by apt-get install of course, and choosing en_US.UTF-8, a message popped up:
locales-all installed, skipping locales generation
Which is understandable. I have just downloaded a package with all of the locales. So why dpkg-reconfigure locales didn't generate it first?