#zig build-obj {
--name test -fno-emit-bin
-Mroot=test.zig
#}

#write test.zig {
const FloatInt = extern union {
    Float: f32,
    Int: i32,
};
export fn entry() void {
    const fi: FloatInt = .{ .Float = 123.45 };
    _ = @tagName(fi);
}
#}
#update
#check errors {
test.zig:7:9: error: union 'test.FloatInt' is untagged
test.zig:1:25: note: union declared here
#}
