I'm having troubles to build GlusterFS-2.0.6-rc2 under Debian 3.1 and GCC 3.3.5 Glusterfs-2.0.2 built just fine.  Commenting out GF_BOOSTER_SUBDIR and Make completes minus Booster.   Not much and issue for me though could be for someone else on an old outdated OS who should really upgrade to something supported. 

localhost:/usr/src/glusterfs-2.0.6rc2# gcc -v 
Reading specs from /usr/lib/gcc-lib/i486-linux/3.3.5/specs
Configured with: ../src/configure -v --enable-languages=c,c++,java,f77,pascal,objc,ada,treelang --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-gxx-include-dir=/usr/include/c++/3.3 --enable-shared --enable-__cxa_atexit --with-system-zlib --enable-nls --without-included-gettext --enable-clocale=gnu --enable-debug --enable-java-gc=boehm --enable-java-awt=xlib --enable-objc-gc i486-linux
Thread model: posix
gcc version 3.3.5 (Debian 1:3.3.5-13)

localhost:/usr/src/glusterfs-2.0.6rc2# CFLAGS="-O0 -g" ./configure --sysconfdir=/etc --prefix=/usr/local/glusterfs-2.0.6-rc2-debug 


Make results: 

make[3]: Entering directory `/usr/src/glusterfs-2.0.6rc2/booster/src'
if /bin/sh ../../libtool --tag=CC --mode=compile gcc -DHAVE_CONFIG_H -I. -I. -I../..  -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -I../../libglusterfsclient/src -I../../libglusterfs/src -DDATADIR=\"/usr/local/glusterfs-2.0.6-rc2-debug/var\" -DCONFDIR=\"/etc/glusterfs\"  -I../../libglusterfsclient/src/ -D_GNU_SOURCE -DGF_LINUX_HOST_OS -fPIC -Wall -pthread  -shared -nostartfiles -O0 -g -MT libglusterfs_booster_la-booster.lo -MD -MP -MF ".deps/libglusterfs_booster_la-booster.Tpo" -c -o libglusterfs_booster_la-booster.lo `test -f 'booster.c' || echo './'`booster.c; \
then mv -f ".deps/libglusterfs_booster_la-booster.Tpo" ".deps/libglusterfs_booster_la-booster.Plo"; else rm -f ".deps/libglusterfs_booster_la-booster.Tpo"; exit 1; fi
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I. -I../.. -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -I../../libglusterfsclient/src -I../../libglusterfs/src -DDATADIR=\"/usr/local/glusterfs-2.0.6-rc2-debug/var\" -DCONFDIR=\"/etc/glusterfs\" -I../../libglusterfsclient/src/ -D_GNU_SOURCE -DGF_LINUX_HOST_OS -fPIC -Wall -pthread -nostartfiles -O0 -g -MT libglusterfs_booster_la-booster.lo -MD -MP -MF .deps/libglusterfs_booster_la-booster.Tpo -c booster.c  -fPIC -DPIC -o .libs/libglusterfs_booster_la-booster.o
booster.c:470: error: syntax error before "__nonnull"
booster.c:472: error: syntax error before "__nonnull"
booster.c:1357: error: syntax error before "__nonnull"
booster.c:1359: error: syntax error before "__nonnull"
make[3]: *** [libglusterfs_booster_la-booster.lo] Error 1
make[3]: Leaving directory `/usr/src/glusterfs-2.0.6rc2/booster/src'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/usr/src/glusterfs-2.0.6rc2/booster'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/usr/src/glusterfs-2.0.6rc2'
make: *** [all] Error 2