perl: warning: Setting locale failed.

This warning message usually appears when the system is unable to set the desired locale. The locale is used to define language, character encoding, and cultural conventions settings for the user's environment.

To fix this issue, you can try the following steps:

1. Check if the locale you want to set is installed on your system using the command `locale -a`.

2. If the desired locale is not installed, you can install it using your distribution's package manager. For example, on Ubuntu, you can install a locale using the command `sudo locale-gen <locale>`.

3. If the desired locale is installed, you can set it as the default locale by adding the following line to your shell configuration file (e.g., `~/.bashrc`):

`export LC_ALL=<locale>`

4. Save the file and reload the shell configuration by running `source ~/.bashrc`.

5. Finally, you can verify that the locale is set correctly by running the command `locale`.

I hope this helps!