I want to upgrade an old (8.3-RC2) FReeBSD installation, but can't install subversion

[Torfinn Ingolfsen]

I have a machine which has an old installation of FreeBSD 8.3 on it:
root at kg-vm2# uname -a
FreeBSD kg-vm2 8.3-RC2 FreeBSD 8.3-RC2 #0: Sat Mar 24 16:15:47 UTC
2012     root at mason.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC
amd64

and I want to update it. Since FreeBSD this old doesn't have svnlite
installed, I fetch a ports tree (no, this machine didn't have one
already) and try to install the subversion port:
root at kg-vm2# cd /usr/ports/devel/subversion
root at kg-vm2# make install
Unknown modifier 't'

"/usr/ports/Mk/bsd.port.mk", line 1727: Malformed conditional
(defined(USE_RC_SUBR) && ${USE_RC_SUBR:tu} != "YES")
Unknown modifier 't'

Unknown modifier 't'

Unknown modifier 't'

"/usr/ports/Mk/bsd.sites.mk", line 956: Malformed conditional
(!empty(_PERL_CPAN_ID) && ${_PERL_CPAN_FLAG:tl} == "cpan")
Unknown modifier 't'

Unknown modifier 't'

"/usr/ports/Mk/bsd.port.mk", line 2858: Unclosed conditional/for loop
"/usr/ports/Mk/bsd.port.mk", line 2858: Unexpected end of file in for loop.

"/usr/ports/Mk/bsd.port.mk", line 6574: Unclosed conditional/for loop
"/usr/ports/Mk/bsd.port.mk", line 6574: Unexpected end of file in for loop.

make: fatal errors encountered -- cannot continue

So I google a bit and find this[1] thread.
Hmm, ok let's try to install bmake then:
root at kg-vm2# cd /usr/ports/devel/bmake
root at kg-vm2# make install
Unknown modifier 't'

Unknown modifier 't'

Unknown modifier 't'

Unknown modifier 't'

Unknown modifier 't'

"/usr/ports/Mk/bsd.sites.mk", line 956: Malformed conditional
(!empty(_PERL_CPAN_ID) && ${_PERL_CPAN_FLAG:tl} == "cpan")
Unknown modifier 't'

Unknown modifier 't'

"/usr/ports/Mk/bsd.port.mk", line 2858: Unclosed conditional/for loop
"/usr/ports/Mk/bsd.port.mk", line 2858: Unexpected end of file in for loop.

"/usr/ports/Mk/bsd.port.mk", line 6574: Unclosed conditional/for loop
"/usr/ports/Mk/bsd.port.mk", line 6574: Unexpected end of file in for loop.

1 open conditional:
     at line 1167 (evaluated to true)
make: fatal errors encountered -- cannot continue

Now, can anyone explain to me how I am going to get an updated source
(/usr/src) onto this machine, without resorting to (to me, totally
unnecessary) unconventional steps?

AFAICT, there is nothing in /usr/ports/UPDATING about this.
So much for POLA.
Bah.

References:
1) https://forums.freebsd.org/viewtopic.php?f=5&t=46291#p258936
-- 
Regards,
Torfinn Ingolfsen