Who's trying what?
The Temple pieces, components, stones have reportedly been ready for years. The Temple could be built within a year of starting.
The vessles for use have been made and priests have been trained int heir use.
DNA has been used to affirm authentic descendents from Aaron.
When the Temple is rebuilt, we can know that there are scant years left until Christ appears in the clouds. Thankfully, even 7 years of horror is a RELATIVELY short time.
Hagee and Lindsey
From what I understand, the Jews have everything on hand that they need to rebuild the Temple. Trouble is, there's a mosque on the Temple Mount property. Scholars believe an earthquake or some traumatic thing will destroy the mosque and then the Jews can build the Temple again. It will be interesting to see how this comes about.