stage2 usingnamespace with private decl causes ambiguous reference

[billzez]

Zig Version

0.10.0-dev.4217+9d8cdb855

Steps to Reproduce

const std = @import("std");

pub const Mixin = struct {
    const X = 1;
};

pub const Thing = struct {
    pub usingnamespace Mixin;
    pub const X = 1;
};

pub fn main() void {
    std.debug.print("{d}\n", .{Thing.X});
}

Expected Behavior

Compiles

Actual Behavior

$ zig build-exe main.zig 
main.zig:13:37: error: ambiguous reference
    std.debug.print("{d}\n", .{Thing.X});
                               ~~~~~^~
main.zig:9:9: note: declared here
    pub const X = 1;
    ~~~~^~~~~~~~~~~
main.zig:4:5: note: declared here
    const X = 1;
    ^~~~~~~~~~~

[nektro]

working as intended imo

[billzez]

Desired or not, it's surprising that usingnamespace consumes private declarations. It's a change in behavior from stage1 and not documented.

[nektro]

oh no, you're right. that is a bug. Thing.X should unambiguously reference only the pub one

[nektro]

it should only be an error if Mixin.X was also pub

[Vexu]

pub only matters if you put Mixin in a separate file in which case the reference becomes unambiguous and compiles. If everything is in the same file then the compile error is correct.

[billzez]

@Vexu - that's actually how I hit this bug. It was in a separate file, and I was confused how a private const in one file used as a mixin was affected by the file that consumed it.

[Vexu]

Was Mixin in the same file and Thing in another? That sounds like #13077

[billzez]

Yes, #13077 looks like my original issue. I thought the above was the simplified version, but it appears this issue and that (#13077) are distinct. I'm not advocating that this above issue be fixed, but I do find it confusing.