Code review comment for ~canonical-is-bootstack/charm-grafana:bug/1876327

Regarding func tests not working for you, in tests/functional/test_deploy.py, there is a snippet:
"""
CHARM_BUILD_DIR = os.getenv('CHARM_BUILD_DIR')
JUJU_REPOSITORY = os.getenv('JUJU_REPOSITORY')
if CHARM_BUILD_DIR is not None:
    GRAFANA_BUILD_DIR = os.path.join(CHARM_BUILD_DIR.rstrip('/'), "grafana")
elif JUJU_REPOSITORY is not None:
    GRAFANA_BUILD_DIR = os.path.join(JUJU_REPOSITORY.rstrip('/'), "builds", "grafana")
else:
    GRAFANA_BUILD_DIR = "/tmp/charm-builds/grafana"
BUNDLE_PATH = os.path.join(GRAFANA_BUILD_DIR, "..", "bundle.yaml")
OVERLAY_PATH = os.path.join(GRAFANA_BUILD_DIR, "..", "overlay.yaml")
"""

"charm build" from charmtools uses /tmp/charm-builds/grafana when no env var is found. Please paste here the failure or file a bug and I will look into it.

Thank you.