Re: Possible to compile tree on a different OS?

[mayuresh@kathe.in]

On Tuesday, June 16, 2020 11:42 AM IST, Ralf Mardorf <ralf-mardorf at riseup.net> wrote: 
 
> 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

You have not understood my requirement.
I want to download the latest FreeBSD source tree on my machine running native Ubuntu only and compile that source tree.
As an example of what's possible under NetBSD, read the snippet (below) from the NetBSD mailing list.

==== NetBSD mailing list snippet ====
as per martin husemann <martin at duskware.de>

cd $(top-dir-where-you-put-the-netsbd-tree)
./build.sh -m evbarm64-el tools kernel=MYKERNEL

to build cross toolchain + a single kernel. This will create "tools" in a
special tool directory (and tell you where).

if you are later working on kernel sources, you can do it manually too:

cd $(top-dir-where-you-put-the-netsbd-tree)/sys/arch/evbarm/conf
$(TOOLDIR)/bin/nbconfig MYKERNEL
cd ../compile/MYKERNEL
$(TOOLDIR)/bin/nbmake-evbarm64-el depend
$(TOOLDIR)/bin/nbmake-evbarm64-el -j 24

lots of variants also work, but these are the two most popular (i think).
==================================

Is such an operation possible with FreeBSD under Ubuntu?

~Mayuresh