When you want to transfer an image with imagetransfer.py, but the image itself doesn't exist on the source wiki, the script stops executing with the error NoPageError.
We maybe should add an option that the script asks the user something like this: "This image doesn't exist. Do you want to skip this? [y]es [n]o"
https://gerrit.wikimedia.org/r/c/pywikibot/core/+/640172 looks cool.