Hello, I merged 5.2.0 into my .propellor, last merge was merging f6797bed. Since the merge, when I try to spin, I get: riva4.ni.fr.eu.org has ipv4 91.121.114.4 ... ok ** warning: Unknown host OS is not supported by this property. CallStack (from HasCallStack): error, called at src/Propellor/Property.hs:350:30 in main:Propellor.Property riva4.ni.fr.eu.org container vz-web2 ... failed riva4.ni.fr.eu.org overall ... failed I have in my config.hs: riva4 :: Host riva4 = host "riva4.ni.fr.eu.org" $ props & ipv4 "91.121.114.4" & stdContainerSpawn "vz-web2" "2g" vzWeb2 stdContainerSpawn :: Systemd.MachineName -> String -> Systemd.Container -> Property (HasInfo + DebianLike) stdContainerSpawn name size container = Lvm.lvFormatted Lvm.YesReallyFormatLogicalVolume (Lvm.LogicalVolume name (Lvm.VolumeGroup "vg0")) size Partition.EXT4 `before` Fstab.mounted "auto" dev dir mempty `before` Systemd.nspawned container `describe` ("container " ++ name) where dev = "/dev/vg0" name dir = "/var/lib/container" name vzWeb2 :: Systemd.Container vzWeb2 = Systemd.debContainer "vz-web2" $ props & osDebian (Stable "stretch") X86_64 & ipv4 "10.42.2.13" I reviewed all changes in propellor, but I cannot find what can cause this. How can I debug this?