Problems Building lang/go120 - /tmp full?

[yancm%sdf.org@localhost]

Hello,
Trying to build lang/go120 from pkgsrc/HEAD on NetBSD 9_current amd64...

I'm getting this:

[ 1095082.9828822] /tmp: write failed, file system is full
# cmd/compile/internal/ssa
compile: writing output: write $WORK/b121/_pkg_.a: no space left on device
go tool dist: FAILED:
/usr/pkgsrc/lang/go120/work/go/pkg/tool/netbsd_amd64/go_bootstrap install
-v cmd/asm cmd/cgo cmd/compile cmd/link: exit status 1
*** Error code 2

Stop.
make[1]: stopped in /usr/pkgsrc/lang/go120
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/lang/go120

local # df
Filesystem    1K-blocks       Used      Avail %Cap Mounted on
/dev/raid0a     1032238     559920     420708  57% /
/dev/raid0f     5160878    1701032    3201804  34% /var
/dev/raid0e    15482670    6188590    8519948  42% /usr
mfs:214          127211          2     120849   0% /tmp
/dev/raid0g     1032238      17092     963536   1% /home
/dev/raid0k    77465122    3178542   70413324   4% /sambashare
/dev/raid0h    10321774    2471190    7334496  25% /usr/src
/dev/raid0i    30965612    6725156   22692176  22% /usr/pkgsrc
/dev/raid0j    10321774    6518750    3286936  66% /usr/obj
kernfs                1          1          0 100% /kern
ptyfs                 1          1          0 100% /dev/pts
procfs                4          4          0 100% /proc
tmpfs           1047960          4    1047956   0% /var/shm
local #
The Makefile does have this entry pointing at /tmp:
# cgo compiles under TMPDIR
TMPDIR?=         /tmp

which I changed to this (and created a clean ./work/tmp)
TMPDIR?=         /usr/pkgsrc/lang/go120/work/tmp

But the build fails the same way...

I'm not used to packages trying to write/build outside of the working
directory and in any event I should have plenty of space available... Any
pointers?
gene