This is perhaps the biggest bikeshedding discussion for tabs vs spaces I've ever seen. Found in a GitHub issue for rustfmt:
https://github.com/rust-lang/style-team/issues/1
And it's utterly fascinating to me for some reason. :blobcat_thisisfine:
On the one side, the pro-spaces camp seems to like spaces because they can force viewers to view code exactly the way the author intended.
On the other side, the pro-tabs camp seems to like tabs because the viewer gets to choose how to view the code, not the author.
It's an irreconcilable difference. No wonder there isn't an answer that can make everyone happy.