port-xen/53053: Building lang/go hangs DOM0 xen kernel

[abs%absd.org@localhost]

>Number:         53053
>Category:       port-xen
>Synopsis:       Building lang/go hangs DOM0 xen kernel
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    port-xen-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Feb 25 01:40:00 +0000 2018
>Originator:     abs%absd.org@localhost
>Release:        NetBSD 8.0_BETA
>Organization:
	
>Environment:
System: NetBSD forsaken.absd.org 8.0_BETA NetBSD 8.0_BETA (GENERIC) #0: Sun Feb 11 02:12:12 GMT 2018 abs%hermes.social-events.net@localhost:/var/obj/nbbuild-8-amd64/objdir/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:
Try to build pkgsrc/lang/go. Output stops at:

    ===> Building for go-1.9.4
    cd /var/obj/pkg/lang/go/work/go/src && env GOROOT_BOOTSTRAP=/usr/pkg/go14 GOROOT
    _FINAL=/usr/pkg/go  /usr/pkg/bin/bash ./make.bash
    ##### Building Go bootstrap tool.
    cmd/dist

Reproduced on two different boxes - an i7 based Dell desktop and
an i5 Thinkpad T420s.

Also tested under -current (kernel only) on same T420s, same issue

NetBSD descent.absd.org 8.99.12 NetBSD 8.99.12 (XEN3_DOM0) #0: Sat Feb 24 14:06:27 UTC 2018  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/xen/compile/XEN3_DOM0 amd64

Typically installed package for go14 has just been installed before ths go build and it ends up corrupted, requiring a pkg_delete go14;pkg_admin rebuild; pkg_add .../go14

>How-To-Repeat:
        Try to build lang/go 
>Fix: