problem installing gcc

[Valerio Filippini <Valerio dot Filippini at pv dot infn dot it>]

686-pc-linux-gnu\
Dear gcc writers,

   I am installing gcc version 3.0 on my Linux machine (i686-pc-linux-gnu)
but I get an error during the bootstrap phase (i get the same error
with version 3.0.1 and 3.0.2). 

My current compiler is:
egcs-2.91.66 19990314/Linux (egcs-1.1.2 release) 

Can you give me any help?
thank you for attention.

============================================================
=================   This is the error ======================
============================================================

gcc  -DIN_GCC -g  -W -Wall -Wwrite-strings -Wstrict-prototypes
-Wmissing-prototypes
-Wtraditional -pedantic -Wno-long-long  -DHAVE_CONFIG_H    -I. -I.
-I../../gcc-3.0.2/gcc -I../../gcc-3.0.2/gcc/. -I../../gcc-3.0.2/gcc/config
-I../../gcc-3.0.2/gcc/../include \
-DSTANDARD_STARTFILE_PREFIX=\"../../../\"
-DSTANDARD_EXEC_PREFIX=\"/usr/local/lib/gcc-lib/\"
-DDEFAULT_TARGET_VERSION=\"3.0.2\"
-DDEFAULT_TARGET_MACHINE=\"i686-pc-linux-gnu\"
-DSTANDARD_BINDIR_PREFIX=\"/usr/local/bin/\"
-DTOOLDIR_BASE_PREFIX=\"../../../../\" `test "X${SHLIB_LINK}" = "X" ||
test "yes" != "yes" || echo "-DENABLE_SHARED_LIBGCC"` `test
"X${SHLIB_MULTILIB}" = "X" || echo "-DNO_SHARED_LIBGCC_MULTILIB"` \
  -c ../../gcc-3.0.2/gcc/gcc.c)
../../gcc-3.0.2/gcc/gcc.c: In function `execute':
../../gcc-3.0.2/gcc/gcc.c:2714: `prus' has an incomplete type
../../gcc-3.0.2/gcc/gcc.c:2715: `RUSAGE_CHILDREN' undeclared (first use in  this function)
../../gcc-3.0.2/gcc/gcc.c:2715: (Each undeclared identifier is reported only once
../../gcc-3.0.2/gcc/gcc.c:2715: for each function it appears in.)
../../gcc-3.0.2/gcc/gcc.c:2716: invalid use of undefined type `struct rusage'
../../gcc-3.0.2/gcc/gcc.c:2717: invalid use of undefined type `struct rusage'
../../gcc-3.0.2/gcc/gcc.c:2717: invalid use of undefined type `struct rusage'
../../gcc-3.0.2/gcc/gcc.c:2720: invalid use of undefined type `struct rusage'
../../gcc-3.0.2/gcc/gcc.c:2720: invalid use of undefined type `struct rusage'
../../gcc-3.0.2/gcc/gcc.c:2721: invalid use of undefined type `struct rusage'
../../gcc-3.0.2/gcc/gcc.c:2721: invalid use of undefined type `struct rusage'
../../gcc-3.0.2/gcc/gcc.c: At top level:
../../gcc-3.0.2/gcc/gcc.c:214: storage size of `rus' isn't known
../../gcc-3.0.2/gcc/gcc.c:214: storage size of `prus' isn't known
make[2]: *** [gcc.o] Error 1
make[2]: Leaving directory `/wrk/gcc/gcc'
make[1]: *** [stage1_build] Error 2
make[1]: Leaving directory `/wrk/gcc/gcc'
make: *** [bootstrap] Error 2