I've patched dozens of pinhole leaks in copper tubing over the years. My technique is to take a piece of 1/2" ID rubber hose and cut off a 1/2" length. This piece of hose then gets cut down one side so it will wrap over the copper tubing. Then take one hose clamp and unscrew it so it will go over the copper, then re-engage the screw. Put the piece of hose over the pinhole, then put the clamp over the hose and tighten it up. Leak stops - magic!
Recently I've changed 95% of my copper over to PEX. You need to buy the crimp tool for the rings, but you'll like the change. Keep in mind that the hot line PEX gets quite a bit longer when it gets warm. Cold line is no issue.