merge branch 'pr-1158'

Closes #1158
LGTMs: @hqhq @cyphar

run.go

@@ -59,6 +59,9 @@ command(s) that get executed on start, edit the args parameter of the spec. See
 		},
 	},
 	Action: func(context *cli.Context) error {
+		if err := checkArgs(context, 1, exactArgs); err != nil {
+			return err
+		}
 		if err := revisePidFile(context); err != nil {
 			return err
 		}