How to Fix Failed to set locale, defaulting to C.UTF-8 in CentOS 8?


As a CentOS 8 user, it can be frustrating to encounter the error message "Failed to set locale, defaulting to C.UTF-8." This error message indicates that the system is unable to set the appropriate language settings and has defaulted to a generic language. This can lead to issues with installing packages, running scripts, and using various applications in CentOS 8. This issue can also affect the overall experience of using CentOS 8.

For example, users may see incorrect date and time formats or incorrect language characters in their terminal prompts or applications. That is why it's crucial for users to address this issue promptly as it can negatively affect their productivity.

In this article, we will explain what locales are and why they are essential for setting up your system correctly. We'll also guide you through the steps needed to fix the "Failed to set locale" error in CentOS 8 so that you can get back on track with your work without any further delays.

Understanding Locales in CentOS 8

The Concept of Locales and How they Work in CentOS 8

Locales are a set of parameters that define the user's language, region, date and time format, character encoding, and other cultural preferences. These settings are vital for ensuring that the system displays information in a way that is culturally and linguistically appropriate for the user. In CentOS 8, locales are defined in the "/etc/locale.conf" file.

The system uses a hierarchy to determine which locale to use. First, it checks the "LC_ALL" variable, which overrides all other settings.

If there is no "LC_ALL" variable or if it is empty, the system checks for individual variables such as "LANG", "LC_CTYPE", "LC_NUMERIC", etc., each of which specifies a particular aspect of the locale. If none of these variables are set or if they have invalid values, the system defaults to using the "C" locale.

The Importance of Setting the Correct Locale for a System

Setting the correct locale is crucial because it affects how text is displayed on your system. For instance, if your default language setting is English (US), but you're working with files or applications containing special characters from another language like German or French and your computer isn’t set up to recognize them correctly – then you may see garbled text on-screen instead of what should be there. If you're working with databases that store data specific to different regions or languages – incorrect locales can cause data corruption issues.

Apart from display issues and data corruption risks caused by incorrect locales; applications running on your system may not behave properly when running external scripts or commands if their environment doesn't match yours in terms of supported languages / character encoding setups which could lead to failures when attempting certain operations such as connecting to remote servers via SSH sessions. It is essential to set the correct locale for your system to ensure a seamless and reliable user experience.

Causes of "Failed to set locale, defaulting to C.UTF-8"

One of the main reasons for encountering the error message "Failed to set locale, defaulting to C.UTF-8" in CentOS 8 is missing or incorrect locale settings. Locale settings determine how your system displays language-specific characters and formats data such as dates and numbers. If these settings are not properly configured, your system may not be able to display certain characters correctly or format data in a way that is familiar or expected.

This can lead to confusion, errors, and frustration for users. Another reason for encountering this issue could be outdated packages.

CentOS 8 is constantly evolving and updating its packages with bug fixes and security patches. If you have outdated packages on your system it could lead to conflicts with newer packages leading up to errors like "Failed to set locale".

Example Scenarios

If you try running a command like "sudo yum update" or any other installation involving a package in CentOS 8, it may fail with the error message: "Failed to set locale, defaulting to C.UTF-8". In this scenario, the cause of the error message may be related to missing or incorrect locale settings that prevent the package from installing correctly.

Alternatively, if you are trying to install software that requires specific locales not installed on your system, you may encounter this error message when installing new packages. For example, if you are trying to install a software tool that only works with Japanese locales but do not have them installed on your system , then this might cause an issue leading up again into the same error message.

Checking Current Locale Settings

To fix the "Failed to set locale, defaulting to C.UTF-8" error in CentOS 8, the first step is to check the current locale settings. You can use the 'locale' command to view your system's current locale settings.

Open a terminal window and type 'locale' without quotes, then press Enter. The output of the 'locale' command will display various categories of locale information, such as LANG, LC_CTYPE, LC_NUMERIC, and more.

The values displayed next to these categories indicate the current locale settings for your system. For example −

LC_CTYPE="en_US.utf8" LC_NUMERIC="en_US.utf8" 
LC_TIME="en_US.utf8" LC_COLLATE="en_US.utf8" 
LC_MONETARY="en_US.utf8" LC_MESSAGES="en_US.utf8" 
LC_PAPER="en_US.utf8" LC_NAME="en_US.utf8" 

If you see "C.UTF-8" in any of these categories instead of a specific language or region code like "en_US", it means that your system is using a fallback locale because it could not find or load a valid one.

Setting a New Locale

The next step in fixing this issue is to set a new locale for your system using the 'localectl' command. This command allows you to set both system-wide and per-user locales on CentOS 8. To change the system-wide default locale with localectl, open a terminal window and run this command as root −

localectl set-locale LANG=language_code

Replace language_code with an appropriate language or region code. For example, if you want to set the default language to US English, you can use −

localectl set-locale LANG=en_US.utf8 

After running this command, restart your system or reboot for the changes to take effect.

Updating Packages

If changing locale settings doesn't work, it is possible that outdated packages are causing this issue. You need to update your packages to ensure that all components of your system are up-to-date and compatible with each other.

To update packages in CentOS 8, open a terminal window and run these commands as root −

dnf clean all dnf update 

The first command clears out cached package metadata and the second command updates all installed packages on your system. This process may take some time depending on the number of updates available.


"Failed to set locale, defaulting to C.UTF-8" error is a common issue in CentOS 8 which can cause frustration for users. However, by following the troubleshooting steps outlined above - checking current locale settings using 'locale' command and setting a new locale using 'localectl', as well as updating outdated packages - users can successfully resolve this issue and improve their experience with CentOS 8. It's important to keep in mind that operating systems like CentOS 8 are complex pieces of software that involve multiple components working together.

In many cases, issues like this can be caused by something as simple as an outdated package or configuration file. By staying up-to-date and following troubleshooting steps like these, users can continue using their systems with ease.

Updated on: 12-Jun-2023

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