“I smell a cave”
Not necessarily. Take the deal with whatever you can get, then declare an emergency to fill any remaining gaps at the border with barriers that the deal does not cover. If Trump plays his cards right the entire border can have a secure wall.
Let’s pray so
Bingo. Take what they give you, so long as it doesn't contain an enforceable prohibition against building a Wall.
Even better, there are some who argue he has the clear authority to build a Wall without a declaration. In any event, he better have a robust and effective construction program or he will be booed out of office by 70% of the voters.