> Is there any way to do this work with an already installed compiler, > ie: change the fixincludes.def on the fly and have the installed > compiler immediately pick up on the changes from the text file?
You need to work in a build tree, modify fixincludes.def and follow the instructions given in section 5. Testing fixes (which may or may not work with the new toplevel bootstrap). Then do 'make install' in the dir. -- Eric Botcazou