How To Fix “Perl warning Setting locale failed” Issue in Debian or Ubuntu

This post will guide you how to fix “perl: Warning : Setting locale failed” issue while update your package index or installing a package in your Ubuntu or Debian Linux. How do I fix this Warning problem on my Debian or Ubuntu Linux system.

perl: warning: Falling back to the standard locale ("C").
Starting multipath daemon: multipathd.
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LANG = "en_US.utf8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C")

To fix this issue in your Ubuntu system, and you need to generat missing locales by running the following locale-gen command, type:

$ sudo locale-gen en_US.UTF-8

Outputs:

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

Then you need to reconfigure locales using the following command:

$ sudo dpkg-reconfigure locales

Outputs:

Generating locales (this might take a while)...
en_AG.UTF-8... done
en_AU.UTF-8... done
en_BW.UTF-8... done
en_CA.UTF-8... done
en_DK.UTF-8... done
en_GB.UTF-8... done
en_HK.UTF-8... done
en_IE.UTF-8... done
en_IL.UTF-8... done
en_IN.UTF-8... done
en_NG.UTF-8... done
en_NZ.UTF-8... done
en_PH.UTF-8... done
en_SG.UTF-8... done
en_US.UTF-8... done
en_ZA.UTF-8... done
en_ZM.UTF-8... done
en_ZW.UTF-8... done
Generation complete.

The dpkg-reconfigure locales command will open a dialog under Debian for selecting the desired locale.