For example the current `anytype` type has replaced `var` and running zig fmt on a project I hadn't updated yet changed all references.
That said, Hello World, when taken seriously, it's not that simple of a program and I'm working on a talk for Zig SHOWTIME[1] about it, titled "Advanced Hello World in Zig".
The TLDR is that Zig never had an easy builtin print function because it's important to let the programmer be precise about whether they want locking (or not) or buffering (or not). That's why the easy print function is in the debug namespace.
[1] https://zig.show