pkg/47891: www/firefox 21.0nb4 Python platform dragonfly3 is not supported

[davshao%gmail.com@localhost]

>Number:         47891
>Category:       pkg
>Synopsis:       www/firefox 21.0nb4 Python platform dragonfly3 is not supported
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jun 05 04:50:00 +0000 2013
>Originator:     David Shao
>Release:        DragonFly 3.5-DEVELOPMENT x86_64
>Organization:
>Environment:
DragonFly 3.5-DEVELOPMENT x86_64
>Description:
After a reinstall from scratch of pkgsrc using current master

commit 0dacd2dada4472530b94a1f13e98ce0f13a5e4f2
Date:   Tue Jun 4 18:35:27 2013 -0700

www/firefox 21.0nb4 fails to even start to build with:

=> Fixing path to python.
cd /usr/pkgsrc/www/firefox/work/mozilla-release && autoconf
cd /usr/pkgsrc/www/firefox/work/mozilla-release/js/src && autoconf
mkdir /usr/pkgsrc/www/firefox/work/mozilla-release/js/src/.deps
=> Modifying GNU configure scripts to avoid --recheck
=> Replacing config-guess with pkgsrc versions
=> Replacing config-sub with pkgsrc versions
=> Replacing install-sh with pkgsrc version
creating cache ./config.cache
checking host system type... x86_64-pc-dragonfly
checking target system type... x86_64-pc-dragonfly
checking build system type... x86_64-pc-dragonfly
checking for mawk... /usr/bin/awk
Using Python from environment variable $PYTHON
Creating Python environment
New python executable in 
/usr/pkgsrc/www/firefox/work/mozilla-release/_virtualenv/bin/python2.7
Also creating executable in 
/usr/pkgsrc/www/firefox/work/mozilla-release/_virtualenv/bin/python
Installing setuptools............done.
Installing pip...............done.
platform dragonfly3 is not supported

Error processing command. Ignoring because optional. 
(optional:setup.py:python/psutil:build_ext:--inplace)
checking Python environment is Mozilla virtualenv... Traceback (most recent 
call last):
  File "<string>", line 1, in <module>
  File 
"/usr/pkgsrc/www/firefox/work/mozilla-release/python/mozbuild/mozbuild/base.py",
 line 15, in <module>
    from mach.mixin.process import ProcessExecutionMixin
  File 
"/usr/pkgsrc/www/firefox/work/mozilla-release/python/mach/mach/mixin/process.py",
 line 29, in <module>
    raise Exception('Could not detect environment shell!')
Exception: Could not detect environment shell!
configure: error: Python environment does not appear to be sane.
*** Error code 1

I don't have any symlinks to python in /usr/pkg/bin as of now.  Nor do I set 
$PYTHON in the environment.
>How-To-Repeat:

>Fix: