Comment 1 for bug 817004

I agree!

Basically, the way I think we should handle this is the use try/except when importing the dependencies and also record which have failed. We can then raise errors when unavailable functionality is called. Tools such as QtQR can catch these errors and display a message to the user that they need to install a particular package.

Packaging wise, I think the zbar/qrencode libraries should be Recommends instead of Depends.