This was using a fresh download of the 4.8 binaries. Do I have to do something else besides that? This seems AIR related w/ this air token in the error:
[mxmlc] /Users/grimlock/Downloads/apache-flex-sdk-4.8.0- incubating-bin/frameworks/air-config.xml(64): Error: unable to open '{airHome}/frameworks/libs/air/airglobal.swc' -omar