Broken procedure for custom package orderers

[LedruRollin]

Environment

• OS : Windows 10
• Rez version : 3.2.1
• Rez python version : 3.9.10

To Reproduce

1. Install Rez as recommended in the doc (link)
2. Add a custom package orderer in the package.py as recommended in the doc (link) :

# package.py
# ...
from rez.version import Version
from rez.package_order import PackageOrder, register_orderer


class MyOrderer(PackageOrder):
    name = "my_orderer"

    def __init__(self, custom_arg: str, **kwargs):
        super().__init__(self, **kwargs)
        self.custom_arg = custom_arg

    def sort_key_implementation(self, package_name: str, version: Version):
        pass

    def __str__(self):
        pass

    def __eq__(self, other):
        pass

    def to_pod(self, other):
        pass

    @classmethod
    def from_pod(cls, data):
        pass


register_orderer(MyOrderer)

package_orderers = [
    {
        "type": "my_orderer",
        "custom_arg": "value here"
    }
]

Expected behavior
Rez should work correctly, for example with a rez-config --source-list

Actual behavior
Rez commands raise errors due to apparent circular dependency. Return of a rez-config --source-list call : error_log.txt

Related Issues/PRs

• PR adding the doc for custom package orderers : Add package orderers documentation #1737
• PR adding package orderers to rezconfig.py : Expose package orderers in rez config #868

Regression
Not known

Workaround
Moving the import statement from rez.packages import iter_packages from rez/package_order.py#L13 to rez/package_order.py#L520 solves the issue. However this being a clean solution remain to be looked at.