ns2 version 2.35~RC6-3 failed to build on amd64 with GCC-4.6/oneiric

ns2 version 2.35~RC6-3 failed to build on amd64 with GCC-4.6/oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110413/+buildjob/2463371

Details about the rebuild:
https://lists.ubuntu.com/archives/ubuntu-devel/2011-April/033042.html

Direct link to the build log: https://launchpad.net/ubuntu/+archive/test-rebuild-20110413/+buildjob/2463371/+files/buildlog_ubuntu-natty-amd64.ns2_2.35%7ERC6-3_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 932 lines into the build log:

mac/mac-802_11.cc:2314:30: warning: 'ap' may be used uninitialized in this function [-Wuninitialized]
mac/mac-802_11.cc: In member function 'void Mac802_11::ProbeHandler()':
mac/mac-802_11.cc:738:4: warning: 'ap' may be used uninitialized in this function [-Wuninitialized]
g++ -c -g -O2 -Wall -Wno-write-strings -DTCP_DELAY_BIND_ALL -DNO_TK -DTCLCL_CLASSINSTVAR -DNDEBUG -DLINUX_TCP_HEADER -DUSE_SHM -DHAVE_LIBTCLCL -DHAVE_TCLCL_H -DHAVE_LIBOTCL1_14 -DHAVE_OTCL_H -DHAVE_LIBTK8_4 -DHAVE_TK_H -DHAVE_LIBTCL8_4 -DHAVE_TCLINT_H -DHAVE_TCL_H -DHAVE_CONFIG_H -DNS_DIFFUSION -DSMAC_NO_SYNC -DCPP_NAMESPACE=std -DUSE_SINGLE_ADDRESS_SPACE -Drng_test -I. -I. -I/usr/include/tclcl -I/usr/include -I/usr/include/tcl -I/usr/include/tcl8.4/tcl-private/generic -I/usr/include/tcl8.4/tcl-private/generic -I/usr/include/pcap -I./tcp -I./sctp -I./common -I./link -I./queue -I./adc -I./apps -I./mac -I./mobile -I./trace -I./routing -I./tools -I./classifier -I./mcast -I./diffusion3/lib/main -I./diffusion3/lib -I./diffusion3/lib/nr -I./diffusion3/ns -I./diffusion3/filter_core -I./asim/ -I./qs -I./diffserv -I./satellite -I./wpan -o mac/mac-802_11Ext.o mac/mac-802_11Ext.cc
In file included from mac/mac-802_11Ext.cc:66:0:
mac/mac-802_11Ext.h: In member function 'u_int32_t PHY_MIBExt::getHdrLen11()':
mac/mac-802_11Ext.h:175:19: error: expected primary-expression before 'struct'
mac/mac-802_11Ext.h:175:41: error: 'dh_body' was not declared in this scope
mac/mac-802_11Ext.h:175:51: error: 'offsetof' was not declared in this scope
mac/mac-802_11Ext.h:177:3: warning: control reaches end of non-void function [-Wreturn-type]
make[1]: *** [mac/mac-802_11Ext.o] Error 1
make[1]: Leaving directory `/build/buildd/ns2-2.35~RC6'
dh_auto_build: make -j1 returned exit code 2
make: *** [build] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110425-0115
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/ns2-2.35~RC6