Having a wireguard interface as the source interface on a GRE tunnel causes a configuration error on boot. The tunnel interface is then left out from the running config, but can be added later by loading the saved config using the load command. This is observed in both 1.3 and rolling versions of 1.4.
My config for the interfaces are:
tunnel tun0 { address 10.68.1.17/30 description "OSPF Encap" encapsulation gre ip { ospf { dead-interval 40 hello-interval 10 network point-to-point priority 1 retransmit-interval 5 transmit-delay 1 } } mtu 1280 remote 10.68.0.2 source-address 10.68.0.9 source-interface wg0 } wireguard wg0 { address 10.68.0.9/30 description "WG for OSPF" mtu 1420 peer FR { address xx.xx.xx.xx allowed-ips 10.68.0.10/32 allowed-ips 10.68.0.2/32 persistent-keepalive 25 port xxxxx preshared-key xxx pubkey xxxx } private-key xxx }
The error outputted in the console: