Comment 2 for bug 1846263

Well, heck. That fixed that, but hilights a bug in charm-tools, that the notion of "fetchers" is limited to specific providers like github, launchpad, etc.:

charmtools.fetchers: git rev-parse HEAD: b'3fe523ffbd0a7c97685f37179bea3ce5ae70e7ae\n'
charmtools.build.fetchers: Copying /home/beisner/.cache/charm/17767/interface/tmp9c_1z0hu to /home/beisner/.cache/charm/17767/interface/openstack-ha
charmtools.build.fetchers: Cleaning up /home/beisner/.cache/charm/17767/interface/tmp9c_1z0hu
charmtools.build.fetchers: Checking layer index: https://juju.github.io/layer-index/interfaces/barbican-hsm.json
charmtools.build.fetchers: Found repo: https://opendev.org/x/charm-interface-barbican-hsm
build: Traceback (most recent call last):
  File "/home/beisner/git/release-tools.round6/barbican/.tox/build/lib/python3.7/site-packages/charmtools/build/builder.py", line 941, in main
    build()
  File "/home/beisner/git/release-tools.round6/barbican/.tox/build/lib/python3.7/site-packages/charmtools/build/builder.py", line 649, in __call__
    self.generate()
  File "/home/beisner/git/release-tools.round6/barbican/.tox/build/lib/python3.7/site-packages/charmtools/build/builder.py", line 592, in generate
    layers = self.fetch()
  File "/home/beisner/git/release-tools.round6/barbican/.tox/build/lib/python3.7/site-packages/charmtools/build/builder.py", line 273, in fetch
    return self.fetch_deps(self.top_layer)
  File "/home/beisner/git/release-tools.round6/barbican/.tox/build/lib/python3.7/site-packages/charmtools/build/builder.py", line 278, in fetch_deps
    self.fetch_dep(layer, results)
  File "/home/beisner/git/release-tools.round6/barbican/.tox/build/lib/python3.7/site-packages/charmtools/build/builder.py", line 307, in fetch_dep
    results["interfaces"].append(iface.fetch())
  File "/home/beisner/git/release-tools.round6/barbican/.tox/build/lib/python3.7/site-packages/charmtools/build/builder.py", line 100, in fetch
    self.directory = path(fetcher.fetch(self.target_repo))
  File "/home/beisner/git/release-tools.round6/barbican/.tox/build/lib/python3.7/site-packages/charmtools/build/fetchers.py", line 150, in fetch
    f, target = self._get_repo_fetcher_and_target(self.repo, dir_)
  File "/home/beisner/git/release-tools.round6/barbican/.tox/build/lib/python3.7/site-packages/charmtools/build/fetchers.py", line 143, in _get_repo_fetcher_and_target
    f = get_fetcher(repo)
  File "/home/beisner/git/release-tools.round6/barbican/.tox/build/lib/python3.7/site-packages/charmtools/fetchers.py", line 375, in get_fetcher
    raise FetchError('No fetcher for url: %s' % url)
charmtools.fetchers.FetchError: No fetcher for url: https://opendev.org/x/charm-interface-barbican-hsm

build: No fetcher for url: https://opendev.org/x/charm-interface-barbican-hsm
ERROR: InvocationError for command '/home/beisner/git/release-tools.round6/barbican/.tox/build/bin/charm-build --log-level DEBUG -o /home/beisner/git/release-tools.round6/barbican/build src' (exited with code 1)