Hi Ingvar,
While using ASDF-INSTALL to get a new noctool setup going, I found that the image package used strings instead of symbols for the packages that it depends on. This confuses the heck out of asdf-install (but seems to work OK for ASDF - HMMM... sounds like it might be a bug in ASDF-INSTALL, but... well, I don't want to spend the time reading the spec to determine that ;P :)
I've attached a modified version of image.asd from image-0.6 - the changes are by no means profound :)
Using the attached image.asd made my asdf-install go very smoothly. :)
If you look at noctool.asd, it too is using strings instead of symbols. I suspect it's more of an issue with ASDF-INSTALL than with the ASDF system definition, myself.
//Ingvar