Hi, I am sorry for reopening this thread. But I am still struggling to get the branch-and-bound depth through a solver-dependent callback. Follows an MWE based on the example provided at here.

```
using JuMP, CPLEX, Test
model = direct_model(CPLEX.Optimizer())
set_silent(model)
MOI.set(model, MOI.NumberOfThreads(), 1)
@variable(model, 0 <= x <= 2.5, Int)
@variable(model, 0 <= y <= 2.5, Int)
@objective(model, Max, y)
function my_callback_function(cb_data::CPLEX.CallbackContext, context_id::Clong)
# preliminary checkings
context_id != CPX_CALLBACKCONTEXT_CANDIDATE && return
ispoint_p = Ref{Cint}()
(CPXcallbackcandidateispoint(cb_data, ispoint_p) != 0 || ispoint_p[]) == 0 && return
# getting depth
depth = Ref{Clong}()
# CPXcallbackgetinfoint(cb_data, CPX_CALLBACK_INFO_NODE_DEPTH, depth)
# CPXcallbackgetinfolong(cb_data, CPX_CALLBACK_INFO_NODE_DEPTH, depth)
CPXcallbackgetinfodbl(cb_data, CPX_CALLBACK_INFO_NODE_DEPTH, depth)
depth > 0 && return
end
MOI.set(model, CPLEX.CallbackFunction(), my_callback_function)
optimize!(model)
```

When executing the above code, the following output is given:

```
ERROR: LoadError: MethodError: Cannot `convert` an object of type Int64 to an object of type CPXCALLBACKINFO
```

As you can see, I already tried replacing the call CPXcallbackgetinfodbl with CPXcallbackgetinfoint and CPXcallbackgetinfolong. But both changes lead to the same error. I suppose that I am using the wrong function or the wrong flag, i.e. I should use something other than CPX_CALLBACK_INFO_NODE_DEPTH. I would like to know if anyone has any documentation about this.

Thank you and best regards.