The dependencies in Alphas are currently >= 2.0.0 and should be >=2.0.0a0 in order to work with Alphas in cases which are not PEP 440-compliant.

According to https://www.python.org/dev/peps/pep-0440/, >= 2.0.0 should also work with alpha/beta releases (a1/a2) but in some cases it does not (https://apache-airflow.slack.com/archives/C0146STM600/p1602774750041800) 

Changing to ">=2.0.0a0" should help.
provider_packages/setup_provider_packages.py
Operators = "Operators"
    Transfers = "Transfers"
    Sensors = "Sensors"
    Hooks = "Hooks"
    Secrets = "Secrets"
class EntityTypeSummary(NamedTuple):
    entities: Set[str]
    new_entities: List[str]
    moved_entities: Dict[str, str]
    new_entities_table: str
    moved_entities_table: str
    wrong_entities: List[Tuple[type, str]]
class VerifiedEntities(NamedTuple):
    all_entities: Set[str]
    wrong_entities: List[Tuple[type, str]]
ENTITY_NAMES = {
    EntityType.Operators: "Operators",
    EntityType.Transfers: "Transfer Operators",
    EntityType.Sensors: "Sensors",
    EntityType.Hooks: "Hooks",
    EntityType.Secrets: "Secrets",
}
TOTALS: Dict[EntityType, List[int]] = {
    EntityType.Operators: [0, 0],
    EntityType.Hooks: [0, 0],
    EntityType.Sensors: [0, 0],
    EntityType.Transfers: [0, 0],