Hi, I'm affected by this bug too.
After some hit and miss, I'm able to reproduce it in a docker container. mkdir /tmp/bug1019188 cd /tmp/bug10109188 cat > Dockerfile <<EOF FROM debian:testing RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get -y install vim-nox vim-addon-manager vim-youcompleteme locales RUN perl -pe 's/^# (en_US.UTF-8)/$1/;' -i /etc/locale.gen && locale-gen -a RUN vam install youcompleteme EOF docker build -t bug10109188 . docker run --rm -it bug10109188 env LANG=en_US.UTF-8 vim On the other hand, enabling youcompleteme via :packadd youcompleteme seems to work without error. Best, E.
