func        output coverage profile information for each function
merge       merge data files together
subtract    subtract one set of data files from another set
intersect   generate intersection of two sets of data files
debugdump   dump data in human-readable format for debugging purposes
`)
	fmt.Fprintf(os.Stderr, "\nFor help on a specific subcommand, try:\n")
	fmt.Fprintf(os.Stderr, "\ngo tool covdata <cmd> -help\n")
	Exit(2)
}