The improvements that Chun Tian identified have been pushed into master on common-lisp.net
I also pushed a test modification that disables testing ecl-make-image on MacOS. At the very least, it doesn't work on Macs with MacPorts (gets confused about which compiler to use with which libraries). This seems like not a problem for ASDF.
I'd welcome any testing that people could do, and plan to release the new version by the end of next week.
Best, r