https://github.com/pydata/pandas/commit/8f3229227856af4feedb5894da9ccd4168a4e2a0 https://github.com/pydata/pandas/commit/eefe71e27131bc4848e549e3688ef6700b57b73a (partial revert) fixing to 4.0.8 seems 4.1 breaks things.