Use :READ-FILE-FORM for defsystem versions
Use ASDF/PACKAGE:SYMBOL-CALL
Specify UTF-8 as file encoding
Replace IOLIB-SOURCE-FILE class with :AROUND-COMPILE wrapper
Specify :UTF-8 as file encoding in all DEFSYSTEMs
Remove redundant OPERATION-DONE-P on TEST-OP
Nicer PERFORM of TEST-OP