What happened:

ERROR - 2021-04-20 08:43:37,220 - distributed.worker.execute.l2800 - ('ready', 'memory')
Traceback (most recent call last):
  File "\miniconda3\lib\site-packages\distributed\worker.py", line 2765, in execute
    self.transition(ts, "memory", value=value)
  File "\miniconda3\lib\site-packages\distributed\worker.py", line 1584, in transition
    func = self._transitions[start, finish]
KeyError: ('ready', 'memory')

We see this key error occasionally during execution of our application. I checked through the worker code and theres already a function defined for this transition, its just not in the _transitions table. Is this an oversight?

What you expected to happen:
I would expect this to not happen

Minimal Complete Verifiable Example:

I don't have one, we just see it sometimes. I'm opening this issue just to see if this is an oversight or not.

Anything else we need to know?:

Environment:

• Dask version: 2021.04.0
• Python version: 3.7
• Operating System: windows
• Install method (conda, pip, source): conda