Logging and sub-tests were added to help debug this problem:
the test passes for ResourceClaim (same defaulting!) and fails
for the list, but only if run together with the other test cases?!
$ go test ./pkg/api/testing
--- FAIL: TestDefaulting (1.76s)
--- FAIL: TestDefaulting/resource.k8s.io/v1alpha3,_Kind=ResourceClaimList (0.01s)
defaulting_test.go:238: expected resource.k8s.io/v1alpha3, Kind=ResourceClaimList to trigger defaulting due to fuzzing
FAIL
FAIL k8s.io/kubernetes/pkg/api/testing 17.294s
FAIL
$ go test -run=TestDefaulting/resource.k8s.io/v1alpha3,_Kind=ResourceClaimList ./pkg/api/testing
ok k8s.io/kubernetes/pkg/api/testing 0.062s
What fixed that problem was increasing the likelihood of generating the right
test object by iterating more often before giving up.