# go help shows overview.
go help
stdout 'Go is a tool'
stdout 'bug.*start a bug report'

# go help bug shows usage for bug
go help bug
stdout 'usage: go bug'
stdout 'bug report'

# go bug help is an error (bug takes no arguments)
! go bug help
stderr 'bug takes no arguments'

# go help mod shows mod subcommands
go help mod
stdout 'go mod <command>'
stdout tidy

# go help mod tidy explains tidy
go help mod tidy
stdout 'usage: go mod tidy'

# go mod help tidy does too
go mod help tidy
stdout 'usage: go mod tidy'

# go mod --help doesn't print help but at least suggests it.
! go mod --help
stderr 'Run ''go help mod'' for usage.'
