compile error – &:not(&)

[kovchiy]

.foo {
    &:not(&_bar) {
        color:red;
    }
}

compiled to:

.foo:not(&_bar) {
    color: red;
}

[SomMeri]

This is a duplicate of #1554. Extend does not support & operator.

[seven-phases-max]

I guess I'll re-open this since it's not related to extend.