ARM: Warning: L6320W: Ignoring --keep command. Cannot find argument '--summary_stderr'. (2 Replies)

I recently switched to uVision 5 (from 4) and added a generic I/O pin class to a project I inherited, and then proceeded to use the class like I've done in many other projects. Unfortunately, when I build it I get this error. project.axf: Warning: L6320W: Ignoring --keep command. Cannot find argument '--summary_stderr'. project.axf: Error: L6218E: Undefined symbol --summary_stderr (referred from anon$$obj.o). The online help for L6320W is not much help