The error message is not helpful at all

[CGQAQ]

Zig Version

0.11.0

Steps to Reproduce and Observed Output

https://godbolt.org/z/nqGW753Yq

Expected Output

Give me the location of my own code

Actual Output

[matu3ba]

const std = @import("std");

pub fn main() !void {
    const logical_ant = 1;
    const result = 15;

    std.log.err("Ant#{}: Scan result: {02X}\n", .{ logical_ant, result });
    // format string is not correct here ^
}

I ran into this too when upgrading an old codebase. There were some format strings I was using that are no longer valid, and I wasn't getting any trace to tell me where the problem was, only the @compileError line in fmt.zig.

Here's a reduction (zig 0.11.0) which hopefully demonstrates the same issue (could be oversimplified though):

pub fn format(comptime x: bool) void {
    _ = x;
    @compileError("error");
}

pub fn main() void {
    format(true);
}

This doesn't print any trace, but if you remove comptime from the argument, it does.

I found some existing issues on the topic of @compileError leaving partial or no trace, but they all seemed to be describing something a little different. E.g. #14492 (comment), #12969, #14335