Error when installing self-building add-on from repo (works fine from local add-ons dir)

Hi All,

A number of people have reported an issue when trying to install my dasher addon.
The following error is thrown when trying to install this (self-building) add-on:

17-10-07 13:52:48 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/aiohttp/web_protocol.py", line 422, in start
    resp = yield from self._request_handler(request)
  File "/usr/lib/python3.6/site-packages/aiohttp/web.py", line 306, in _handle
    resp = yield from handler(request)
  File "/usr/lib/python3.6/site-packages/hassio/api/util.py", line 31, in wrap_api
    answer = await method(api, *args, **kwargs)
  File "/usr/lib/python3.6/site-packages/hassio/api/addons.py", line 176, in install
    addon.install(version=version), loop=self.loop)
  File "/usr/lib/python3.6/site-packages/hassio/addons/addon.py", line 467, in install
    if not await self.docker.install(version):
  File "/usr/lib/python3.6/site-packages/hassio/dock/util.py", line 18, in wrap_api
    return await method(api, *args, **kwargs)
  File "/usr/lib/python3.6/concurrent/futures/thread.py", line 55, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/lib/python3.6/site-packages/hassio/dock/addon.py", line 198, in _install
    return self._build(tag)
  File "/usr/lib/python3.6/site-packages/hassio/dock/addon.py", line 211, in _build
    image = self.docker.images.build(**build_env.get_docker_args(tag))
  File "/usr/lib/python3.6/site-packages/docker/models/images.py", line 175, in build
    raise BuildError(chunk['error'])
docker.errors.BuildError: invalid reference format: repository name must be lowercase

Anyone know what causes the error “repository name must be lowercase”?
The repo is “https://github.com/james-fry/hassio-addons”, so no non-lowercase chars in there.

This add-on used to work perfectly, so I guess something has changed in the way hass.io 0.64 builds add-ons… ?

It should be noted that when I install (i.e. build) the exact same add-on from local add-ons dir it works fine.

Looks like it might be a docker version issue.
I’m upgrading docker to 17.05+ and see what happens.
Still if this is the case, its weird that local build still works…

Working with Docker 17.09 (was previously 17.06)