It would be nice to keep the spawned process from starting the given command until we're done configuring the network, on --config-net (by checking that addresses and routes we configured are in fact there), and in general until the tap device is ready. See also the discussion around: https://archives.passt.top/passt-dev/20221104015336.3831673-1-sbrivio@redhat.com/
Fixed by commit d8921dafe506 ("pasta: Wait for tap to be set up before spawning command").