docker build PKM install error on Ubuntu (with workaround)
The "docker build" command to install PKM on Ubuntu 18.04 may throw an error, like this:
$ docker build -t pkm -f docker/Dockerfile "docker build" requires exactly 1 argument. See 'docker build --help'. Usage: docker build [OPTIONS] PATH | URL | -
If so, you have to add a dot at the end of the command (then it works fine):
$ docker build -t pkm -f docker/Dockerfile .
This behaviour is somewhat weird... and deserves to be documented (or fixed ?)