core: Alexa Discovery Error: self.entity.attributes[vacuum.ATTR_FAN_SPEED_LIST] KeyError: 'fan_speed_list'

Testing Alexa HAASKA Lambda discovery throws an error for my vacuum domain. I’m guessing my ecobot vacuum doesn’t have fan speed options. I can’t get Alexa to discover the vacuum because of this error. If I don’t include the vacuum in the include_domains, everything works fine.

Environment

arch | x86_64
-- | --
dev | false
docker | true
hassio | true
os_name | Linux
os_version | 4.19.104
python_version | 3.7.7
timezone | America/Denver
version | 0.108.9
virtualenv | false

• Home Assistant Core release with the issue: 108.9
• Last working Home Assistant Core release (if known): Unknown
• Operating environment (Home Assistant/Supervised/Docker/venv): Above
• Integration causing this issue: Alexa
• Link to integration documentation on our website: https://www.home-assistant.io/integrations/alexa.smart_home

alexa:
  smart_home:
    locale: en-US
    endpoint: "https://api.amazonalexa.com/v3/events"
    client_id: xxx
    client_secret: xxx
    filter:
      include_domains:
        - switch
        - light
        - climate
        - vacuum
        - lock

Traceback/Error logs

Amazon Dev console reports:

Execution result: succeeded

but returns null and the logs show an internal server error:

[ERROR]	2020-05-07T16:16:57.347Z	xxx	HomeAssistant error 500 Internal Server Error

HA Log:

2020-05-07 10:16:57 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/aiohttp/web_protocol.py", line 418, in start
    resp = await task
  File "/usr/local/lib/python3.7/site-packages/aiohttp/web_app.py", line 458, in _handle
    resp = await handler(request)
  File "/usr/local/lib/python3.7/site-packages/aiohttp/web_middlewares.py", line 119, in impl
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/real_ip.py", line 39, in real_ip_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/ban.py", line 72, in ban_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/auth.py", line 127, in auth_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/view.py", line 123, in handle
    result = await result
  File "/usr/src/homeassistant/homeassistant/components/alexa/smart_home_http.py", line 120, in post
    hass, self.smart_home_config, message, context=core.Context(user_id=user.id)
  File "/usr/src/homeassistant/homeassistant/components/alexa/smart_home.py", line 39, in async_handle_message
    response = await funct_ref(hass, config, directive, context)
  File "/usr/src/homeassistant/homeassistant/components/alexa/handlers.py", line 84, in async_api_discovery
    for alexa_entity in async_get_entities(hass, config)
  File "/usr/src/homeassistant/homeassistant/components/alexa/handlers.py", line 85, in <listcomp>
    if config.should_expose(alexa_entity.entity_id)
  File "/usr/src/homeassistant/homeassistant/components/alexa/entities.py", line 289, in serialize_discovery
    capabilities.append(i.serialize_discovery())
  File "/usr/src/homeassistant/homeassistant/components/alexa/capabilities.py", line 205, in serialize_discovery
    capability_resources = self.capability_resources()
  File "/usr/src/homeassistant/homeassistant/components/alexa/capabilities.py", line 1503, in capability_resources
    speed_list = self.entity.attributes[vacuum.ATTR_FAN_SPEED_LIST]
KeyError: 'fan_speed_list'

Pretty sure this is just a result of a breaking change somewhere along the line. I’m not a programmer so I don’t know how to fix the relevant code.

I have a similar issue with the climate domain; I’m going to open up another issue for that.

Thanks!