If Guile CVS is built with --disable-deprecated GCC 3.4 fails to build
eval.c. The problem is that the function scm_macroexp() is used in
line 1941 of eval.c. The prototype is not declared in eval.h if
deprecated functions are disabled and the function definition starts
further below in line 2131. I solved this problem locally by adding a
forward declaration to eval.c.