I am not sure why this occurs but it can be more of a configure error than a gcc error. Moreover trying buiding with same options but end a directory like --prefix=/a/ instead of --prefix=/a . Can tell me how you are building the stuff. Like the steps and commands you used.
I copied the libgloss and the newlib directory of the latest newlib release (1.14) into the gcc source tree and configured with the following parameters:
--target=powerpc-eabi --prefix=/usr/local/gcc-powerpc-eabi --with- local-prefix=/usr/local/gcc-powerpc-eabi --enable-languages=c,c++ -- with-newlib
Thanks for your help. Cheers, Hermann