Comment 2 for bug 1668353

I have run into this problem in the past when doing automated bare-metal testing. My "solutions" are:

1. We test when kernels hit -proposed. We wait approx. 2 hrs. after LP says the packages are in proposed to let publishing "settle" before kicking off testing.
2. I do my deployments using MAAS. After deploying a system, one of the first things I do is remove /etc/apt/apt.conf.d/90curtin-aptproxy which has caused problems in the past with me being able to get to a -proposed kernel.