> So many variants of that code

Indeed… That evolution makes perfect sense. A lot of Go developers independently arrived at similar request coalescing patterns around that time, especially in caching, RPC, and high concurrency systems. I have an older implementation from personal 2013-era Go projects that follows almost the same approach.

What is nice about open source is not necessarily the novelty of every individual idea, but having a well-tested, shared implementation the community can converge on. Your work on singleflight clearly became that reference point for the Go ecosystem, and it is cool to see the lineage from dl.google.com to groupcache, x/net, the standard library, and now all the downstream variants.