kernel clean failed: failed to run ["make" "-j" "64" "ARCH=x86_64" "distclean"]: exit status 2
Makefile:83: *** Cannot find a vmlinux for VMLINUX_BTF at any of "  ../../vmlinux /sys/kernel/btf/vmlinux /boot/vmlinux-5.9.0-0.bpo.5-cloud-amd64".  Stop.
make[2]: *** [Makefile:192: sched_ext_clean] Error 2
make[1]: *** [/syzkaller/jobs/linux/kernel/Makefile:1361: sched_ext] Error 2
make[1]: *** Waiting for unfinished jobs....
make: *** [Makefile:240: __sub-make] Error 2