Non-standard archive formats may result in files being re-archived at
each nmake execution. We have seen one cross compiler tool set,
CCsparc and arsparc from CenterLine with this problem.
The archive libraries created by arsparc were using the standard
magic number causing nmake to think they were standard format, but
nmake was actually unable to completely parse their contents. The result
.o files with names greater than 16 characters
were not recognized in the archive causing nmake to add them again to the
archive. Normally if nmake does not recognize the format of an archive
it will run the appropriate command to get the archive's table of
contents. But the case when the magic number indicates a standard
archive but the contents is slightly non-standard will cause problems.