go/src/cmd/go/internal/modinfo/info.go

type ModulePublic …

type ModuleError …

type moduleErrorNoMethods …

// UnmarshalJSON accepts both {"Err":"text"} and "text",
// so that the output of go mod download -json can still
// be unmarshaled into a ModulePublic during -reuse processing.
func (e *ModuleError) UnmarshalJSON(data []byte) error { … }

func (m *ModulePublic) String() string { … }