How to fix setlocale error in Raspberry Pi OS

You'll get the following error in Raspberry Pi OS when locale is not properly set.

-bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8)

You can easily fix this via Raspberry Pi Software Configuration Tool (raspi-config).

1. Run raspi-config from the command line.
   

   sudo raspi-config

2. Choose Localisation Options from the main interface.
   
3. Choose Change Locale from the menu.
   
4. De-select locales that you don't need (optional). en_GB.UTF-8 UTF-8 is installed by default and could be removed.
   
5. Select en_US.UTF-8 UTF-8 from the list and press Ok.
   
6. Select en_US.UTF-8 in the next screen
   
7. The selected locales will be generated, and you should no longer get the error.
   

   Generating locales (this might take a while)...
     en_US.UTF-8... done
   Generation complete.