Enum imported from another module raises "Incompatible types error"

[abprime]

The following code runs fine without any mypy error

# file_type.py
from enum import Enum
from sqlalchemy.dialects.postgresql import ENUM

class FileType(str, Enum):
    CSV = "CSV"
    XLSX = "XLSX"

file_type_db_enum = ENUM(FileType, name="file_type")

# input_file.py
from file_type import FileType
from sqlalchemy import Column
from sqlalchemy.dialects.postgresql import ENUM
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()
class InputFile(Base):
    file_type: FileType = Column(ENUM(FileType, name="file_type"))

But changing input file to following throws mypy error

# input_file.py
from file_type import file_type_db_enum
from sqlalchemy import Column
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()
class InputFile(Base):
    file_type: FileType = Column(file_type_db_enum)

input_file.py:7: error: Incompatible types in assignment (expression has type "Column[NullType]", variable has type "FileType")

Note : I am importing the file_type_db_enum, as it is being reused by multiple other models, and also, because graphene-sqlalchemy wants it to be declared this way, Otherwise it generates conflicts for multiple objectType with the same name.

Expected behavior
This should not raise any errors.

To Reproduce

# file_type.py
from enum import Enum
from sqlalchemy.dialects.postgresql import ENUM

class FileType(str, Enum):
    CSV = "CSV"
    XLSX = "XLSX"

file_type_db_enum = ENUM(FileType, name="file_type")

# input_file.py
from file_type import file_type_db_enum
from sqlalchemy import Column
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()
class InputFile(Base):
    file_type: FileType = Column(file_type_db_enum)

Error

input_file.py:7: error: Incompatible types in assignment (expression has type "Column[NullType]", variable has type "FileType")

Versions.

• OS: Windows 10
• Python: 3.8.10
• SQLAlchemy: 1.4.22
• mypy: 0.910
• SQLAlchemy2-stubs: 0.0.2a8