Saw this today. I was on the serial console so kernel messages were coming to the console. Not sure if it is an issue or can safely be ignored.
[root@localhost ~]# rpm-ostree status [ 23.266519] gpg2 (1095) used greatest stack depth: 10704 bytes left State: idle Deployments: ● fedora-atomic:fedora/rawhide/x86_64/atomic-host Version: Rawhide.20170624.n.0 (2017-06-24 11:11:38) Commit: a69db8341de093a19e18c87db1b4fafd61f180d75635c7cfb77097f3b999b525 GPGSignature: 1 signature Signature made Sat 24 Jun 2017 07:12:03 AM EDT using RSA key ID F55E7430F5282EE4 Good signature from "Fedora 27 <fedora...@fedoraproject.org>"