One of Horizon's requirements is pyscss package. Which had last release over 4 years ago... Two days ago setuptools v46 got released. One of changes was drop of Features feature. Today Kolla builds started to fail: INFO:kolla.common.utils.horizon:Collecting pyScss===1.3.4 INFO:kolla.common.utils.horizon: Downloading http://mirror.ord.rax.opendev.org:8080/pypifiles/packages/1d/4a/221ae7561c8f... (120 kB) INFO:kolla.common.utils.horizon: ERROR: Command errored out with exit status 1: INFO:kolla.common.utils.horizon: command: /var/lib/kolla/venv/bin/python -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-rr0db3qs/pyScss/setup.py'"'"'; __file__='"'"'/tmp/pip-install-rr0db3qs/pyScss/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-install-rr0db3qs/pyScss/pip-egg-info INFO:kolla.common.utils.horizon: cwd: /tmp/pip-install-rr0db3qs/pyScss/ INFO:kolla.common.utils.horizon: Complete output (5 lines): INFO:kolla.common.utils.horizon: Traceback (most recent call last): INFO:kolla.common.utils.horizon: File "<string>", line 1, in <module> INFO:kolla.common.utils.horizon: File "/tmp/pip-install-rr0db3qs/pyScss/setup.py", line 9, in <module> INFO:kolla.common.utils.horizon: from setuptools import setup, Extension, Feature INFO:kolla.common.utils.horizon: ImportError: cannot import name 'Feature' Are there any plans to fix it? pyscss project got issue: https://github.com/Kronuz/pyScss/issues/385 In Kolla I made ugly workaround: https://paste.centos.org/view/2e29d284 What are plans of Horizon team?