Yes, I would not just patch this section of tubing unless it is necessary, only temporary and if using some of the ideas given by others in these posts.
Something made the tube or something crack right there at that point because of flexing or vibration.
You should fix it permanently by eliminating flex by using flexible hose or supporting tubing rigidly at that point and junction.
If at the stove
; get a short, threaded propane rated hose section and attach to the stove
and the other end of the hose attach somehow to a newly cut section of the existing copper line. But....There should not be any joints or connections along the feed line while inside the hull
, except at the stove, then exiting the hull
, at the regulator
before the tank itself unless the joint or connection is sealed in a compartment that vents down and out near the waterline outside the hull. But....you should prevent the flexing at the point you got the tube or ferrule to crack, prevent that flexing of the copper tubing there, either sagging and not supported or swinging of the stove caused the crack and the dangerous leak.