add assert to make sure zero isn't enabled with 1bit-* (#1169)

deepspeed/runtime/engine.py

@@ -778,6 +778,7 @@ class DeepSpeedEngine(Module):
             from deepspeed.ops.lamb import FusedLamb
             optimizer = FusedLamb(model_parameters, **optimizer_parameters)
         elif self.optimizer_name() == ONEBIT_ADAM_OPTIMIZER:
+            assert not self.zero_optimization(), "1bit-Adam is not compatible with ZeRO"
             from deepspeed.runtime.fp16.onebit.adam import OnebitAdam
             optimizer = OnebitAdam(model_parameters, self, **optimizer_parameters)
             if not self.fp16_enabled():
@@ -785,6 +786,7 @@ class DeepSpeedEngine(Module):
                     f'Currently the convergence of 1-bit Adam is only verified under FP16'
                 )
         elif self.optimizer_name() == ONEBIT_LAMB_OPTIMIZER:
+            assert not self.zero_optimization(), "1bit-Lamb is not compatible with ZeRO"
             from deepspeed.runtime.fp16.onebit.lamb import OnebitLamb
             optimizer = OnebitLamb(model_parameters, self, **optimizer_parameters)
             if not self.fp16_enabled():