Parallels: skip missing paths when looking for unnecessary files

builder/parallels/common/artifact.go

@@ -29,6 +29,14 @@ func NewArtifact(dir string) (packer.Artifact, error) {
 	files := make([]string, 0, 5)
 	visit := func(path string, info os.FileInfo, err error) error {
 		if err != nil {
+			if os.IsNotExist(err) {
+				// It's possible that the path in question existed prior to visit being invoked, but has
+				// since been deleted. This happens, for example, if you have the VM console open while
+				// building. Opening the console creates a <vm name>.app directory which is gone by the time
+				// visit is invoked, resulting in err being a "file not found" error. In this case, skip the
+				// entire path and continue to the next one.
+				return filepath.SkipDir
+			}
 			return err
 		}
 		for _, unnecessaryFile := range unnecessaryFiles {