Hi again! In Section 32.4 of The NetBSD Guide, <http://www.netbsd.org/docs/guide/en/chap-build.html#chap-boot-cross-build-kernel>
the following line is used for build.sh: ./build.sh -U -u -j2 -O ~/obj -m evbarm -a aarch64 kernel=MYKERNEL Then, it is explicitly mentioned: ``Notice that update ("-u") was specified, the tools are already built, there is no reason to rebuild all of the tools''. With this sentence, it seems that the option `-u' prevents the above line to build the tools, if they have already been built and they are already present in the `~/obj' directory. I do not know build.sh so well, but this seems to be not correct. In fact, when running a build with the above line, it is explicitly printed ===> Building kernel without building new tools with or without `-u', and it fails if tools are not present (instead of building them). So, I think this sentence should be reviewed, according to the point the author wanted to highlight. (Maybe, the sentence would be correct if this line was used instead: ./build.sh -U -u -j2 -O ~/obj -m evbarm -a aarch64 tools kernel=MYKERNEL Then, build.sh maybe will check for tools and, because of `-u', if they are present and up-to-date, they are not built again. I don't think, however, this was what the author wanted to show.) I opened a thread in @netbsd-users about this feature and other ones: <http://mail-index.netbsd.org/netbsd-users/2021/05/03/msg026958.html> Bye! Rocky