In the case where someone is using the ask and tell only, there's no reason for SMAC to know about the target_function at hand, however it's required by the abstract facade.

I can get around this pretty easily as I'm familiar enough with SMAC but it would nice not to have to do these hacky work-arounds.

optimizer = HyperparameterOptimizationFacade(
    scenario=Scenario(...),
    target_function="dummy"  # Smac things this is a program it should run
)

The reason for this is we are building light wrappers around some optimizers that support ask and tell and not relying on SMAC to actually evaluate the target_function itself.