Just FYI, I found that it's not possible to build an i686 kernel on x86_64 (in 2.6.23.1-42.fc8), because this happens: + gcc -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i686 -mtune=generic -fasynchronous-unwind-tables -o scripts/modsign/mod-extract scripts/modsign/mod-extract.c In file included from /usr/include/features.h:359, from /usr/include/stdio.h:28, from scripts/modsign/mod-extract.c:12: /usr/include/gnu/stubs.h:7:27: error: gnu/stubs-32.h: No such file or directory It's not important why stubs-32.h does not exist in glibc-headers. The problem is using -m32 for a host executable, because the kernel.spec has this: gcc $RPM_OPT_FLAGS -o scripts/modsign/mod-extract scripts/modsign/mod-extract.c I suspect that hardcoding gcc -O would work just dandily, but on the other hand it's unclear if we want to bother fixing it. Thoughts?