The build fails almost immediately like so:

make[1]: Entering directory `/tmp/uml/linux/arch/um/sys-i386/util'
gcc-2.95.4 -c mk_thread_user.c 
gcc-2.95.4 -D__KERNEL__ -I/tmp/uml/linux/include -Wall -Wstrict-prototypes -Wno-trigraphs -O2 -fno-strict-aliasing -fno-common  -U__i386__ -Ui386 -DUM_FASTCALL -g -D__arch_um__ -DSUBARCH=\"i386\" -D_LARGEFILE64_SOURCE -I/tmp/uml/linux/arch/um/include -Derrno=kernel_errno -I/tmp/uml/linux/arch/um/kernel/skas/include -c mk_thread_kern.c 
In file included from /tmp/uml/linux/include/asm/ptrace-generic.h:26,
                 from /tmp/uml/linux/include/asm/ptrace.h:10,
                 from /tmp/uml/linux/include/linux/ptrace.h:24,
                 from /tmp/uml/linux/include/linux/binfmts.h:4,
                 from /tmp/uml/linux/include/linux/sched.h:9,
                 from mk_thread_kern.c:3:
/tmp/uml/linux/arch/um/include/skas_ptrace.h:9: redefinition of `struct ptrace_faultinfo'
/tmp/uml/linux/arch/um/include/skas_ptrace.h:14: redefinition of `struct ptrace_ldt'
make[1]: *** [mk_thread_kern.o] Error 1
make[1]: Leaving directory `/tmp/uml/linux/arch/um/sys-i386/util'
make: *** [arch/um/sys-i386/util/mk_thread] Error 2

because skas_ptrace.h is being included after
include/asm-um/arch/ptrace.h, which defines the same structures.

bzipped preprocessed source: