After building the kernel I get following message:
make[1]: Leaving directory '/home/drasko/grapheneos-RP1A.200720.009.2020.10.01.23/kernel/google/crosshatch/out'

and had these two somewhat warning(?) messages:
Symbol __typeid__ZTSFvPvP21cam_req_mgr_core_linkiP23cam_req_mgr_add_requestP19cam_req_mgr_req_tblP28cam_req_mgr_connected_deviceE_global_addr too long for kallsyms (134 vs 128).
Please increase KSYM_NAME_LEN both in kernel and kallsyms.c

Can I ignore these messages and continue with building GrapheneOS?
  KSYM    .tmp_kallsyms2.o
Symbol __typeid__ZTSFvPvP21cam_req_mgr_core_linkiP23cam_req_mgr_add_requestP19cam_req_mgr_req_tblP28cam_req_mgr_connected_deviceE_global_addr too long for kallsyms (134 vs 128).
Please increase KSYM_NAME_LEN both in kernel and kallsyms.c