Possible to compile tree on a different OS?

[Ralf Mardorf]

On Tue, 16 Jun 2020 07:16:37 +0200, mayuresh at kathe.in wrote:
>The NetBSD folks have mechanisms in place to allow compiling
>(including cross-compiling) their entire (or partial) source tree
>under a different operating system. Eg. I can download and compile the
>NetBSD source tree under a Ubuntu system using GNU build tools.
>
>Does FreeBSD have such facilities in place too?

By googling I couldn't find a script such as
https://www.netbsd.org/docs/guide/en/chap-build.html , but a howto

https://marcelog.github.io/articles/cross_freebsd_compiler_in_linux.html