../../../../../../base/sys/kernel/kern_main.cxx: In function `int
main(int)':
../../../../../../base/sys/kernel/kern_main.cxx:52: invalid
redeclaration of `main()'
../../../../../../base/sys/kernel/kern_main.cxx:67: as `main(int)'
make[4]: *** [kern_main.o] Error 1
editing the declaration of main(void) to main(int) is simple enough and the build procedes
make -j -k -l 5 install