port-sparc/57961: Set extraction failed with "Unexpected EOF"

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

>Number:         57961
>Category:       port-sparc
>Synopsis:       Set extraction failed with "Unexpected EOF"
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-sparc-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Feb 26 12:10:00 +0000 2024
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current, source date 2024.02.25.20.25.09
>Organization:
>Environment:
System: NetBSD
Architecture: sparc
Machine: sparc
>Description:

A recent sparc install on the TNF testbed failed with the error messages

  gzip: (stdin): unexpected end of file
  tar: End of archive volume 1 reached
  tar: Unexpected EOF on archive file
  tar: Failed seek on file ./etc/skel/.shrc (Invalid argument)

This has happened a few times before, all this year.  The console logs
are at:

  http://releng.netbsd.org/b5reports/sparc/2024/2024.01.07.18.42.37/install.log
  http://releng.netbsd.org/b5reports/sparc/2024/2024.01.27.12.14.58/install.log
  http://releng.netbsd.org/b5reports/sparc/2024/2024.02.03.12.57.12/install.log
  http://releng.netbsd.org/b5reports/sparc/2024/2024.02.25.20.25.09/install.log

For reference, there were similar errors on i386 in 2017-2018 when it
was having trouble reading the install CD.  Here are the logs from the
first and last one of those:

  http://releng.netbsd.org/b5reports/i386/2017/2017.11.05.07.03.37/install.log
  http://releng.netbsd.org/b5reports/i386/2018/2018.10.15.05.44.09/install.log

>How-To-Repeat:

>Fix: