establish a properish Docker environment

Dockerfile

@@ -6,6 +6,14 @@ RUN apt-get update && apt-get install -y \
      build-essential chrpath socat cpio python python3 python3-pip python3-pexpect \
      xz-utils debianutils iputils-ping
 
+RUN apt-get update && apt-get install -y locales \
+ && locale-gen en_US.UTF-8 \
+ && update-locale LANG=en_US.UTF-8
+
+ENV LANG=en_US.UTF-8
+ENV LANGUAGE=en_US:en
+ENV LC_ALL=en_US.UTF-8
+
 RUN useradd -ms /bin/bash yocto
 USER yocto
 WORKDIR /home/yocto