To keep the Go distribution honest? Eventually, we'd want as much
convergence as possible, forking the library would make it easier to
diverge without consequences.
but it's not a question of forking the library. there's a ton of stuff under go/src,
so what makes libbio special? why not just compile the one there for its use, which is the one it expects?
the output goes into a go-specific target directory; what else will care?