Be clearer in our error messages, #'canonicalize-inst-pair, #'canonicalize-spec lisp/ChangeLog addition: 2010-08-15 Aidan Kehoe <kehoea@parhasard.net> * specifier.el (canonicalize-inst-pair, canonicalize-spec): If a specifier tag set is correct, but an instantiator is not in an accepted format, don't error with the message "Invalid specifier tag set". Also, when we error, use error-symbols, for better structured error handling and more ease when testing. tests/ChangeLog addition: 2010-08-15 Aidan Kehoe <kehoea@parhasard.net> * automated/lisp-tests.el: (not, not, invalid-argument, invalid-argument): Check that error messages from the image specifier instantiator code are clearer than they used to be.