port-sparc/53014: NetBSD/sparc no longer installs

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         53014
>Category:       port-sparc
>Synopsis:       NetBSD/sparc no longer installs
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-sparc-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Feb 12 15:10:00 +0000 2018
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current, source date 2018.02.05.20.27.06
>Organization:

>Environment:
System: NetBSD
Architecture: sparc
Machine: sparc
>Description:

The sparc test runs on the TNF testbed are failing when booting 
the INSTALL kernel, with:

panic: init died (signal 4, exit 0)
Frame pointer is at 0xf4d4f8b8
Call traceback:
  pc = 0xf0025348  args = (0x0, 0x5, 0x0, 0x0, 0xf4d4f9e0, 0xf0002000) fp = 0xf4d4f928
  pc = 0xf0152ff8  args = (0x104, 0x0, 0xf01fea10, 0xf4d4faa8, 0xf0365a10, 0xf0361000) fp = 0xf4d4f998
  pc = 0xf0153024  args = (0xf01fea10, 0xf4d4faa8, 0xf0364c00, 0xf0365800, 0xf0365890, 0x104) fp = 0xf4d4f9f8
  pc = 0xf011f9b8  args = (0xf01fea10, 0x4, 0x0, 0x0, 0x44000e4, 0x4400fe4) fp = 0xf4d4fa60
  pc = 0xf01349d8  args = (0xf05315e0, 0x0, 0x4, 0xf034c0dc, 0xf05315e0, 0xf0560d58) fp = 0xf4d4faf8
  pc = 0xf0024a18  args = (0xf05315e0, 0x4, 0xfffdffff, 0x2, 0x1e, 0xf0560d58) fp = 0xf4d4fb60
  pc = 0xf0024ba0  args = (0xf05315e0, 0xf4d4fc48, 0xf4d4fc20, 0x0, 0xf0560d58, 0xf4d4ffb0) fp = 0xf4d4fbc0
  pc = 0xf01340d8  args = (0xf4d4ff10, 0xf0531784, 0xf0584000, 0xf4d4ffb0, 0xef7ffce0, 0xf05315e0) fp = 0xf4d4fde0
  pc = 0xf013419c  args = (0xf05315e0, 0xf4d4ff10, 0xf0531784, 0x0, 0xf05315e0, 0x0) fp = 0xf4d4fe40
  pc = 0xf0032bd8  args = (0xb, 0xf0584000, 0xf0531784, 0xf4d4ff10, 0x0, 0x400) fp = 0xf4d4fea0
  pc = 0xf0008524  args = (0x9, 0x286, 0xef7ff000, 0xf4d4ffb0, 0xe, 0x0) fp = 0xf4d4ff50
  pc = 0xffffffa2  args = (0x0, 0x0, 0x20, 0x5e, 0xf0351900, 0xf0351a40) fp = 0xef7fff20

The last successful install was from source date 2018.02.03.11.30.01,
and the first usuccessful one was from source date 2018.02.05.20.27.06.

>How-To-Repeat:

Attempt to install NetBSD-current/sparc, or examine the logs,
for example:

  http://releng.netbsd.org/b5reports/sparc/2018/2018.02.12.02.15.31/install.log

>Fix: