Octavia-diskimage-retrofit hook failed: "install"

Hi,

Anyone know how to fix this hook failed install here’s the log’s Thanks.

root@juju-977d31-0-lxd-5:/var/lib/juju/agents/unit-octavia-diskimage-retrofit-0/charm# ./hooks/install
Traceback (most recent call last):
File “./hooks/install”, line 8, in
basic.bootstrap_charm_deps()
File “lib/charms/layer/basic.py”, line 31, in bootstrap_charm_deps
execd_preinstall()
File “lib/charms/layer/execd.py”, line 114, in execd_preinstall
execd_run(‘charm-pre-install’, execd_dir=execd_dir)
File “lib/charms/layer/execd.py”, line 71, in execd_run
for submodule_path in execd_submodule_paths(command, execd_dir):
File “lib/charms/layer/execd.py”, line 52, in execd_submodule_paths
for module_path in execd_module_paths(execd_dir):
File “lib/charms/layer/execd.py”, line 38, in execd_module_paths
execd_dir = default_execd_dir()
File “lib/charms/layer/execd.py”, line 32, in default_execd_dir
return os.path.join(os.environ[‘JUJU_CHARM_DIR’], ‘exec.d’)
File “/usr/lib/python3.6/os.py”, line 669, in getitem
raise KeyError(key) from None
KeyError: ‘JUJU_CHARM_DIR’
root@juju-977d31-0-lxd-5:/var/lib/juju/agents/unit-octavia-diskimage-retrofit-0/charm#