Hello World sample doesn't work in Windows

[ZeikJT]

The example given here: https://ziglang.org/learn/samples/#hello

As a beginner in zig, running it and seeing this mess wasn't fun:

lib\std\os\windows.zig:2126:13: error: unable to evaluate comptime expression
            asm (
            ^~~
lib\std\os\windows.zig:2135:15: note: called at comptime from here
    return teb().ProcessEnvironmentBlock;
           ~~~^~
lib\std\io.zig:19:27: note: called at comptime from here
        return windows.peb().ProcessParameters.hStdOutput;
               ~~~~~~~~~~~^~
lib\std\io.zig:30:40: note: called at comptime from here
    return .{ .handle = getStdOutHandle() };
                        ~~~~~~~~~~~~~~~^~
C:\Users\zeik\Documents\zig-testing\test.zig:3:32: note: called at comptime from here
const stdout = std.io.getStdOut().writer();
               ~~~~~~~~~~~~~~~~^~
C:\Users\zeik\Documents\zig-testing\test.zig:3:41: note: initializer of container-level variable must be comptime-known
const stdout = std.io.getStdOut().writer();
               ~~~~~~~~~~~~~~~~~~~~~~~~~^~

I usually assume hello world is the baseline for getting started and this was a shock. Had I misconfigured something? How? zig was a single executable, the sample on the landing page which was much more complicated worked fine.

I eventually dug up an old closed issue that explained the problem: ziglang/zig#6845 (comment)
The solution was really simple, if a bit gross, and moving that getStdOut call into the function did indeed fix the issue.

But might be worth mentioning in a note on the page or having both examples? zig beginners will struggle unnecessarily otherwise. Thanks!

EDIT: Just noticed that the Zigg Zagg example does in fact have this done in the Windows-friendly way, inside the function: https://ziglang.org/learn/samples/#zigg-zagg

[ajferrario]

For anyone looking to copy-paste the working code.

const std = @import("std");

pub fn main() !void {
    const stdout = std.io.getStdOut().writer();
    try stdout.print("hello world!\n", .{});
}