Running as the default user Jenkins uses it doesn’t seem to have access to
wherever the artifacts from the previous steps get stored, so it fails to
extract them. Hopefully running as root will let it access them.
The Build/HTML stage needs the Emacs image because it uses Emacs to convert the
org files into html files. The Build/CSS stage runs in an image defined by the
Dockerfile in this repository, installing just make, npm, and lessc to convert
the less files into CSS files. And the Deploy step needs to upload using rsync
overs ssh.
