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Setting Up a UTF-8 Locale

You need a UTF-8 locale to run some Ruby applications. For example, we have found that RubyGems and ruby/spec need such a locale.

This is not needed if the $LANG environment variable is already set and:

locale

shows no ="C" and no warning. Instead, all values should be "en_US.UTF-8" or other regions but still .UTF-8.

Fedora-based: RHEL, Oracle Linux, etc #

export LANG=en_US.UTF-8

Debian-based: Ubuntu, etc #

Ubuntu

The Ubuntu version of locale-gen supports arguments, so it is easy:

sudo apt-get install -y locales
sudo locale-gen en_US.UTF-8
export LANG=en_US.UTF-8

Non-Ubuntu

Debian and other non-Ubuntu do not support locale-gen arguments. Instead you need to modify /etc/locale.gen:

# Uncomment the en_US.UTF-8 line in /etc/locale.gen
sudo sed -i '/en_US.UTF-8/s/^# //g' /etc/locale.gen

# locale-gen generates locales for all uncommented locales in /etc/locale.gen
sudo locale-gen
export LANG=en_US.UTF-8

For Dockerfile’s:

# Uncomment the en_US.UTF-8 line in /etc/locale.gen
RUN sed -i '/en_US.UTF-8/s/^# //g' /etc/locale.gen
# locale-gen generates locales for all uncommented locales in /etc/locale.gen
RUN locale-gen
ENV LANG=en_US.UTF-8