How to fix perl: warning: Please check that your locale settings in APT

First, see which locales are currently available:

locale -a

This lists all installed locales. Common ones are en_US.UTF-8, C, and C.UTF-8.

If you need a specific locale that's missing, generate it:

sudo locale-gen en_US.UTF-8

Then update the system locale configuration:

sudo dpkg-reconfigure locales

Select at least one locale (usually en_US.UTF-8) and confirm it as the default.

Add these variables to your shell profile (~/.bashrc, ~/.bash_profile, or ~/.zshrc):

export LC_ALL=en_US.UTF-8
export LANG=en_US.UTF-8
export LANGUAGE=en_US.UTF-8

Then reload your shell:

source ~/.bashrc

If you're connecting remotely via SSH, your client machine's locale variables may be forwarded to the server. On your local machine, edit ~/.ssh/config:

Host *
    SendEnv LANG LC_*

Change to:

Host *
    SendEnv LANG

Or comment out the SendEnv line entirely to prevent locale forwarding.

If you need an immediate solution without reconfiguring the system:

export LC_ALL=C

Or:

export LC_ALL=C.UTF-8

This disables locale-specific behavior and resolves the warning. This is temporary and only lasts for the current session.