https://en.cppreference.com/w/cpp/memory/unique_ptr/~unique_ptr
unique_ptr's dtor requires that the deleter must not throw. And yet, we're trying to use a unique_ptr to trigger a throw in unit tests, via the destructor ~TestAssertionFailure() noexcept(false).

Well it doesn't matter if the object is marked noexcept(false) or not. An object with a throwing destructor CANNOT be destroyed by a unique_ptr going out of scope. It's UB.

I think this means that any ASSERT failure in our test framework is UB.

https://github.com/mongodb/mongo/blob/master/src/mongo/unittest/unittest.cpp#L598

We can fix by just using something other than std::unique_ptr that doesn't have this restriction and is friendly to exception propagation out of destructors.