stage2: usingnamespace can create ambiguous reference

[slimsag]

Zig Version

0.10.0-dev.3551+92568a009

Steps to Reproduce

The following project builds fine with stage1, but not with -fno-stage1. I encountered this trying to build the new mach/gpu library with stage2:

main.zig:

pub const foo = 666;

pub usingnamespace @import("sub.zig");
const sub = @import("sub.zig");

test {
    _ = sub.bar;
}

sub.zig:

const foo = @import("main.zig").foo;

pub const bar = struct {
    bar: u32 = foo,
};

test {
    _ = foo;
}

Expected Behavior

unsure if this should work, or if stage2 is just being more (correctly) strict here.

Actual Behavior

% zig build test -fno-stage1
/Users/slimsag/Desktop/hexops/mach/gpu/test/src/sub.zig:1:32: error: ambiguous reference
const foo = @import("main.zig").foo;
            ~~~~~~~~~~~~~~~~~~~^~~~
/Users/slimsag/Desktop/hexops/mach/gpu/test/src/main.zig:1:5: note: declared here
pub const foo = 666;
~~~~^~~~~~~~~~~~~~~
/Users/slimsag/Desktop/hexops/mach/gpu/test/src/sub.zig:1:1: note: declared here
const foo = @import("main.zig").foo;
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~