$ echo 'Příliš žluťoučký kůň úpěl ďábelské ódy' > /tmp/utf8-test
$ watch -tn5 "cat /tmp/utf8-test"
Pli luouk k pl belsk dy

It's sad to see another thing (beside [bug 801626]) with the same command
that simply works in Debian but fails in Fedora.

Admittedly, there is some relevant code (proc/escape.c), just one or more
preconditions may not be met using the distro default locale (and more or
less also the environment) as indicated by following external tests:

$ { cat <<EOF
#include <stdlib.h>
#include <stdio.h>
int main(int argc, char *argv[]) {
    printf("MB_CUR_MAX: %d\n", MB_CUR_MAX);
}
EOF
} | gcc -xc - -o test
$ ./test
> MB_CUR_MAX: 1

(would need to be 2+?)

$ python -c 'import locale; print locale.nl_langinfo(locale.CODESET)'
> ANSI_X3.4-1968

(would need to be 'UTF-8'?)


Locale diagnostics (NB: I tried "localectl set-keymap UTF-8" prior to
                    the above test but to no effect)

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

$ localectl
>   System Locale: LANG=en_US.UTF-8
>       VC Keymap: UTF-8
>      X11 Layout: n/a

$ rpm -qf $(which watch) $(which localectl)
> procps-ng-3.3.3-4.20120807git.fc18.x86_64
> systemd-201-2.fc18.6.x86_64


Please, make UTF-8 work out-of-the-box.