Installation fails on my Debian server

[Falco]

@DustVoice

I, [2019-03-17T20:16:52.419559 #14]  INFO -- : > cp /var/www/discourse/config/nginx.sample.conf /etc/nginx/conf.d/discourse.conf
cp: cannot create regular file '/etc/nginx/conf.d/discourse.conf': No such file or directory

This is a very strange error. I would say either docker is broken or the docker FS is busted.

@DustVoice

The command sudo apt list --installed | grep -i docker produces the following output:

docker/stable,now 1.5-1+b1 amd64  [installiert]
docker-ce/stretch,now 5:18.09.3~3-0~debian-stretch amd64  [installiert]

Do you have two dockers installed?