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

#write test.zig {
const U = union(enum) {
    A: type,
};
const S = struct {
    u: U,
};
export fn entry() void {
    comptime var v: S = undefined;
    v.u.A = U{ .A = i32 };
}
#}
#update
#check errors {
test.zig:9:8: error: use of undefined value here causes illegal behavior
#}
