ports/185217: portupgrade: Building ports using a symbolic link in place of /usr/ports is broken

[ap at bnc.net]

>Number:         185217
>Category:       ports
>Synopsis:       portupgrade: Building ports using a symbolic link in place of /usr/ports is broken
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-ports-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Dec 27 03:20:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Charlie &
>Release:        FreeBSD 9.1-RELEASE-p8 amd64
>Organization:
<organization of PR author (multiple lines)>
>Environment:
System: FreeBSD s51.wo-uk.net 9.1-RELEASE-p8 FreeBSD 9.1-RELEASE-p8 #15 r257373: Wed Oct 30 08:28:01 CET 2013 root at s51.wo-uk.net:/usr/obj/usr/src/sys/GENERIC amd64


        system isn't important

>Description:
Running on a system with small /usr partition and some large empty space on some other partition using symbolic links from /usr/xxxx to /space/xxx has been working since FreeBSD 1.0. But for a few weeks updat
ing ports on systems like that has been broken:

portupgrade portupgrade
[...]
===>  Building package for portupgrade-2.4.11.2_1,2
Creating package /space/ports/ports-mgmt/portupgrade/work/portupgrade-2.4.11.2_1,2.tbz
Registering depends: ruby19-bdb-0.6.6_1 db41-4.1.25_4 ruby-1.9.3.448,1 libexecinfo-1.1_3 libffi-3.0.13 libyaml-0.1.4_2.
Registering conflicts: portupgrade-devel-*.
Creating bzip'd tar ball in '/space/ports/ports-mgmt/portupgrade/work/portupgrade-2.4.11.2_1,2.tbz'
tar: could not chdir to '/space/ports/ports-mgmt/portupgrade/work/stage/space/local'

Using nullfs for a loopback mount will solve this mess...

>How-To-Repeat:
mv /usr/local /somewhereelse
ln -s /somewhereelse/local /usr
portupgrade <something>


>Fix:
rm /usr/local ; mkdir /usr/local; mount_nullfs /space/local /usr/local
>Release-Note:
>Audit-Trail:
>Unformatted: