Printing with leading newline breaks build test output

[ieeemma]

Zig Version

0.11.0-dev.2969+855493bb8

Steps to Reproduce and Observed Behavior

const std = @import("std");

pub fn main() void {}

test {
    std.debug.print("\nNew line!\n", .{});
    return error.ThisIsAnError;
}

Put this in a blank zig project and run zig build test. This causes this output:

run test: error: 'test_0' failed: New line!
/home/emma/zig-bugs/newline/src/main.zig:7:5: 0x20efe9 in test_0 (test)
    return error.ThisIsAnError;
    ^
run test: error: m

First, the leading newline before the message is stripped, and second an erroneous run test: error: m is printed.

Expected Behavior

Expected an output like this:

run test: error: 'test_0' failed:
New line!
/home/emma/zig-bugs/newline/src/main.zig:7:5: 0x20efe9 in test_0 (test)
    return error.ThisIsAnError;
    ^

[nektro]

duplicate #15091

since #14647 stdout is reserved for the runner in tests and it expects tests not to print. the issue is a discussion to change (or not) that assumption