What causes the 'BFD: Dwart Error:' ?

[PRC]

This error occurs only if the link flags contain `-r'.
Something must be different between linking relocatable objects 
and linking non-relocatable objects.

>I think bfd is getting confused, trying to append data to the should- 
>be-empty bss section, and accidentally overwriting the debugging info. 
>This data is all zeros.  Leading zeros in the debug info will be 
>ignored, until it gets to non-zero info, which will then fail to parse 
>giving various curious error messages.
>
>Jim