That's not accurate. It's also pruning from the resulting list the commit authors for which GitHub is unable to associate a GitHub account with a given contributor; it simply doesn't attempt to represent contributors who are not (known) GitHub users.
(That isn't to say there's any significance here to Vim; the Vim repo does genuinely obscure patch authors by not using the appropriate fields to capture that information—most commits, going by Git metadata, are attributed to Bram using that method. But the statement "all GitHub's doing is looking at commit authors", strictly speaking, is not true.)
That's not accurate. It's also pruning from the resulting list the commit authors for which GitHub is unable to associate a GitHub account with a given contributor; it simply doesn't attempt to represent contributors who are not (known) GitHub users.
(That isn't to say there's any significance here to Vim; the Vim repo does genuinely obscure patch authors by not using the appropriate fields to capture that information—most commits, going by Git metadata, are attributed to Bram using that method. But the statement "all GitHub's doing is looking at commit authors", strictly speaking, is not true.)
Previously: GitHub's "Contributors" graphs are unreliable for working out who really works on a given repo. <https://news.ycombinator.com/item?id=31421107>