I have

    $ locale
    LANG=en_GB.UTF-8
    LC_CTYPE=ru_RU.UTF-8
    LC_NUMERIC=en_GB.UTF-8
    LC_TIME=en_GB.UTF-8
    LC_COLLATE=ru_RU.UTF-8
    LC_MONETARY=ru_RU.UTF-8
    LC_MESSAGES=en_GB.UTF-8
    LC_PAPER=ru_RU.UTF-8
    LC_NAME=ru_RU.UTF-8
    LC_ADDRESS=ru_RU.UTF-8
    LC_TELEPHONE=ru_RU.UTF-8
    LC_MEASUREMENT=ru_RU.UTF-8
    LC_IDENTIFICATION="en_GB.UTF-8"
    LC_ALL=

    $ locale -a
    C
    en_GB.utf8
    POSIX
    ru_RU.utf8

But 'man' gives the error:

    $ man
    man: can't set the locale; make sure $LC_* and $LANG are correct
    What manual page do you want?

I set all LC_* to 'en_GB.UTF-8', but the error doesn't disappear. If I set the LC_ALL, the error disappears:

    $ LC_ALL=en_GB.UTF-8 man
    What manual page do you want?

Does 'man' really need to mandatory LC_ALL set? (If so, this is stupid behavior because many people have different locales in different LC_* variables and they can't use LC_ALL.)