Installation on Mac failure

I followed this guide to install HA on a Mac Mini but got a bunch of errors.

Could someone please point me in the right direction as to what went wrong?

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2019-03-21 20:51:09 INFO (MainThread) [homeassistant.loader] Loaded persistent_notification from homeassistant.components.persistent_notification
2019-03-21 20:51:09 INFO (MainThread) [homeassistant.setup] Setup of domain introduction took 0.0 seconds.
2019-03-21 20:51:09 INFO (MainThread) [homeassistant.setup] Setting up lovelace
2019-03-21 20:51:09 INFO (MainThread) [homeassistant.setup] Setup of domain lovelace took 0.0 seconds.
2019-03-21 20:51:09 ERROR (MainThread) [homeassistant.setup] Unable to set up dependencies of api. Setup failed for dependencies: http
2019-03-21 20:51:09 ERROR (MainThread) [homeassistant.setup] Setup failed for api: Could not set up all dependencies.
2019-03-21 20:51:09 ERROR (MainThread) [homeassistant.setup] Unable to set up dependencies of websocket_api. Setup failed for dependencies: http
2019-03-21 20:51:09 ERROR (MainThread) [homeassistant.setup] Setup failed for websocket_api: Could not set up all dependencies.
2019-03-21 20:51:09 ERROR (MainThread) [homeassistant.setup] Unable to set up dependencies of auth. Setup failed for dependencies: http
2019-03-21 20:51:09 ERROR (MainThread) [homeassistant.setup] Setup failed for auth: Could not set up all dependencies.
2019-03-21 20:51:09 ERROR (MainThread) [homeassistant.setup] Unable to set up dependencies of onboarding. Setup failed for dependencies: auth, http
2019-03-21 20:51:09 ERROR (MainThread) [homeassistant.setup] Setup failed for onboarding: Could not set up all dependencies.
2019-03-21 20:51:09 ERROR (MainThread) [homeassistant.setup] Unable to set up dependencies of frontend. Setup failed for dependencies: api, websocket_api, http, system_log, auth, onboarding
2019-03-21 20:51:09 ERROR (MainThread) [homeassistant.setup] Setup failed for frontend: Could not set up all dependencies.
2019-03-21 20:51:09 INFO (SyncWorker_2) [homeassistant.util.package] Attempting install of sqlalchemy==1.2.18
2019-03-21 20:51:28 INFO (MainThread) [homeassistant.setup] Setting up recorder
Exception in thread Recorder:
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/threading.py", line 917, in _bootstrap_inner
self.run()
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/homeassistant/components/recorder/__init__.py", line 171, in run
from .models import States, Events
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/homeassistant/components/recorder/models.py", line 6, in <module>
from sqlalchemy import (
ModuleNotFoundError: No module named 'sqlalchemy'

2019-03-21 20:51:38 WARNING (MainThread) [homeassistant.setup] Setup of recorder is taking over 10 seconds.