port pkg missing PackageMaker.app

[Blair Zajac]

I'm looking at distributing MacPorts in a custom prefix using Munki and 
instead of packaging an entire MacPorts install using pkg and mpkg, 
however, this fails with the following error:

bash-3.2# port -v mpkg gperf
--->  Fetching archive for gperf
--->  Unpacking tbz2 archive for gperf 3.0.4_2
--->  Extracting gperf-3.0.4_2.darwin_11.x86_64.tbz2
x ./
x ./+COMMENT
x ./+CONTENTS
x ./+DESC
x ./+PORTFILE
x ./+STATE
x ./opt/
x ./opt/local-10.7-2012-08/
x ./opt/local-10.7-2012-08/bin/
x ./opt/local-10.7-2012-08/share/
x ./opt/local-10.7-2012-08/share/doc/
x ./opt/local-10.7-2012-08/share/info/
x ./opt/local-10.7-2012-08/share/man/
x ./opt/local-10.7-2012-08/share/man/man1/
x ./opt/local-10.7-2012-08/share/man/man1/gperf.1.gz
x ./opt/local-10.7-2012-08/share/info/gperf.info
x ./opt/local-10.7-2012-08/share/doc/gperf.html
x ./opt/local-10.7-2012-08/bin/gperf
--->  Archive gperf-3.0.4_2.darwin_11.x86_64.tbz2 unpacked
Warning: PackageMaker.app not found; you may need to install it or set 
packagemaker_path in macports.conf
--->  Creating pkg for gperf-3.0.4
pax: Write block size of 19 is not a 512 byte multiple
Command failed: cd 
/opt/local-10.7-2012-08/var/macports/build/_opt_local-10.7-2012-08_var_macports_sources_rsync.macports.org_release_ports_devel_gperf/gperf/work/destroot 
&& /bin/pax -x /usr/bin/cpio -w -z . > 
/opt/local-10.7-2012-08/var/macports/build/_opt_local-10.7-2012-08_var_macports_sources_rsync.macports.org_release_ports_devel_gperf/gperf/work/gperf-3.0.4.pkg/Contents/Archive.pax.gz
Exit code: 1


Having never worked with pkg and mpkg, can this easily be moved over to 
use pkgbuild instead?  Would this be pretty straight forward for me to 
code in MacPorts?  Or should I find PackageMaker?  I'm using Xcode 4.5.2.

Thanks,
Blair