I've added a QA warning to autotools.eclass so that now using its functions outside of src_unpack throws is reported to the users (and thus to the developers to fix it). I'm filing bugs for the packages I can easily find being doing this through a simple grep on the tree. If you fixed the issue in the last version of an ebuild and I still opened this bug, please don't close it until you removed that ebuild from the tree. Thanks for the cooperation.
Created attachment 143600 [details] Revised ebuild fixing QA problems
Changed the ebuild and renamed to mini-xml-2.4-r1.ebuild to fix above mentioned QA problems - compiles and tests OK on x86
Fixed autotools calls, please open a new bug for other issues.