process killed: text file modification

Hello,

I'm trying to build a few things from ports on an rpi3, the ports 
collection is mounted over NFS from another machine. When it's trying to 
build pkg i'm getting the error message in syslog:

rpi3 kernel: pid 4451 (sh), uid 0, was killed: text file modification

The report to pkg_at_:
https://lists.freebsd.org/pipermail/freebsd-pkg/2017-March/002048.html

In ports-mgmt/pkg's config.log It fails at the following entry:
configure:3726: checking whether we are cross compiling
configure:3734: cc -o conftest -O2 -pipe  -Wno-error 
-fno-strict-aliasing   conftest.c  >&5
configure:3738: $? = 0
configure:3745: ./conftest
configure:3749: $? = 137
configure:3756: error: in `/usr/ports/ports-mgmt/pkg/work/pkg-1.10.0':
configure:3760: error: cannot run C compiled programs.
If you meant to cross compile, use `--host'.
See `config.log' for more details

# uname -a
FreeBSD rpi3 12.0-CURRENT FreeBSD 12.0-CURRENT #0 r314949: Thu Mar 9 
08:58:46 CET 2017 
aegir_at_marvin.harmless.hu:/tank/rpi3/crochet/work/obj/arm64.aarch64/tank/rpi3/src/sys/AEGIR 
arm64

I have no idea what's causing it, it should pretty much work out of the 
box. Could someone please explain me what's going on here, what's 
causing it and how can I fix it?

Best regards,
-czg