I got fiasco-1.1-oskit.tar.bz2.tar and fiasco-1.1.tar.bz2.tar, and unpacked them into one directory. I have build the kernel successfully with gcc 3.x. But when my gcc updated to 4.1.2, I can't build the kernel at all. The two tar-balls are unpacked to the directory /storage/soft/l4/tmp/fiasco- 1.1 And the error I got is as follow: make[3]: Entering directory `/storage/soft/l4/tmp/fiasco-1.1/oskit/libkern' gcc -c -MD -DHAVE_CONFIG_H -I. -I../libkern/x86 -I../libkern/x86/trap -I../libkern/x86/pc -I../libkern -iquote -I.. -I.. -I../flux/c -nostdinc -g -O2 -march=i586 -Wall ../libkern/x86/base_cpu_init.c In file included from ../libkern/x86/base_cpu_init.c:22: ../flux/x86/base_trap.h:105: error: array type has incomplete element type make[3]: *** [base_cpu_init.o] Error 1 make[3]: Leaving directory `/storage/soft/l4/tmp/fiasco-1.1/oskit/libkern' make[2]: *** [libkern/all.MAKE] Error 2 make[2]: Leaving directory `/storage/soft/l4/tmp/fiasco-1.1/oskit' make[1]: *** [all] Error 2 make[1]: Leaving directory `/storage/soft/l4/tmp/fiasco-1.1/oskit' make: *** [../oskit] Error 2 Quite strange. Does anyone compile fiasco1.1 successfully with gcc 4.x?