A quick, dirty, and permanent fix for an emulsion pinhole is to stab the emulsion with a dress-makers pin right on top of the pinhole. Yes! Push the pin in right down to the film base if necessary. The resulting concave dimple diverts enlarger light away from the defect and the black spot in the positive disappears...more or less. This technique was a favourite with the old press photographers who could not wait for red opaque or spotting dye to dry.