On my "Available updates" page I get error messages when there are custom modules in use:

Failed to get available update data for one project.

Is there any way to avoid this? Either by setting up some sort of feed for custom modules (probably not practical in most situations!) or by excluding custom modules from the list?

(As an aside, it seems like a design flaw in the Update manager module to give an error for custom modules. If they are in the custom directory inside modules then it can easily determine that they are custom, and clearly should not expect to receive update data for them from the same source as contributed modules.)

Is there any solution to this other than filing a bug report and hoping the maintainer agrees with my perspective? (Or hacking the module myself.)