Since 7.20181121 Debian has been seeing test suite failures, on the mips autobuilders and on the amd64 CI infrastructure, but not on the amd64 autobuilders.
I am inclined to think that there are several bugs here: the test suite is overly sensitive to its environment and can fail in different ways in different environments. What's mysterious is why all this started happening so recently.
It seems unlikely to me that anyone has time to fix these bugs before the upcoming Debian freeze. Getting git-annex v7.x into buster is a priority. Maybe the test suite should be disabled during the package build, since it's flaky? I'd like to hear Joey's opinion on doing that.