The en_US.UTF-8 locale needs glibc-langpack-en on Oracle Linux 8+

Author: eregon

doc/user/utf8-locale.md

@@ -21,6 +21,7 @@ Instead, all values should be `"en_US.UTF-8"` or other regions but still `.UTF-8
 ### Fedora-based: RHEL, Oracle Linux, etc
 
 ```bash
+sudo dnf install glibc-langpack-en
 export LANG=en_US.UTF-8
 ```