mjhjmtu

I recently updated my Arch Linux server and during that process tmux got updated. I was using tmux while the upgrade was going on and used it afterwards, but all during the same SSH session.

Now, however, whenever I try to issue any tmux command I get this error:

tmux: need UTF-8 locale (LC_CTYPE) but have ANSI_X3.4-1968

Here's the output from locale -a on the server:

$ locale -a
C
POSIX

and on my machine (Ubuntu 15.10):

$ locale -a
C
C.UTF-8
en_AG
en_AG.utf8
en_AU.utf8
en_BW.utf8
en_CA.utf8
en_DK.utf8
en_GB.utf8
en_HK.utf8
en_IE.utf8
en_IN
en_IN.utf8
en_NG
en_NG.utf8
en_NZ.utf8
en_PH.utf8
en_SG.utf8
en_US.utf8
en_ZA.utf8
en_ZM
en_ZM.utf8
en_ZW.utf8
POSIX

What's going on and how do I fix it?

The same exact thing happened to me. Building on what Thomas said above, I was able to fix it by uncommenting en_US.UTF-8 UTF-8 in my /etc/locale.gen file (previously none of the lines had been uncommented), then running locale-gen.

Perhaps your upgrade replaced the locale alias you were using and did not provide a useful upgrade path to the new name(s). You can regenerate locale information on the server, but keep in mind that the problem may be in your /etc/locale.gen or locale.conf file.

Further reading:

• 
  Locale (Arch wiki)


• Why is almost every program complaining about my locale?


• cannot set locale (systemd)

Following this link solves my problem:

sudo localectl set-locale LANG=en_CA.UTF-8
# or change to en_US.UTF-8 depends on your locale-gen

it generates a file /etc/locale.conf that fixes this issue

echo "LC_ALL=en_US.UTF-8" >> /etc/environment

echo "en_US.UTF-8 UTF-8" >> /etc/locale.gen

echo "LANG=en_US.UTF-8" > /etc/locale.conf

locale-gen en_US.UTF-8

I had this one as well. My solution was …

apt search locales

I got a list, then install this …

apt install locales-all