I started using Jigl for my private photo gallery, and quite like it. In the process of generating the HTML, I received the following error:

convert: missing an image filename `0601091401.jpg' @ convert.c/ConvertImageCommand/2775

The problem turned out to be a zero byte file named 0601091401.jpg, but ImageMagick puked on it because it wasn't actually a regular file; rather, it was a symlink to that empty file. Apparently ImageMagick doesn't respond kindly to nonsense like that. The solution was just to remove the source file and the offending symlink.