The sale will almost certainly be reported by the trust but, with respect to the basis, that would depend upon state law and the type of trust.
Typically, in a joint trust, a step-up in basis occurs upon the first to die with another step-up occurring upon the death of the remaining spouse. This presumes the property is includable in the decedent's gross estate, which is virtually always the case.
There are variations upon the foregoing theme so you need to know the precise terms of the trust.