Variant is masculine in French. Well, the feminine form “variante” exists as well, but is not used in this context. Also, both the masculine and feminine forms

Variant is masculine in French. Well, the feminine form “variante” exists as well, but is not used in this context. Also, both the masculine and feminine forms, “nu” and “nue”, are pronounced exactly the same. “Le variant nu” in French would always be ambiguous.