// PreferredStream returns the tools stream used to search for tools, based
// on the required version, whether devel mode is required, and any user specified stream.
func PreferredStream(vers *version.Number, forceDevel bool, stream string) string {
// If the use has already nominated a specific stream, we'll use that.
if stream != "" && stream != ReleasedStream {
return stream
}
// If we're not upgrading from a known version, we use the
// currently running version.
if vers == nil {
vers = &version.Current.Number
}
// Devel versions are alpha or beta etc as defined by the version tag.
// The user can also force the use of devel streams via config.
if forceDevel || vers.IsDev() {
return DevelStream
}
return ReleasedStream
}
