Greenplum – Upgrading Database with PostGIS Extension

We've got a number of 4.2.3.2 Greenplum databases that are running PostGIS 1.4. We are trying to get these databases onto a more recent version of Greenplum, such as 4.3.8.1 or the re-released version of 4.3.9.1, but we're running into a mess of issues when attempting to upgrade PostGIS to version 2.0. We've attempted a number of different ways to upgrade the database without compromising data and functions that rely on PostGIS 1.4, but it looks like when we run the gppkg utility with the new PostGIS extensions we only get errors, similar to the following:

gppkg -i postgis-ossv2.0.3_pv2.0.1_gpdb4.3orca-rhel5-x86_64.gppkg 
20160919:13:21:20:024675 gppkg:s-md-pv-gp-01-01:gpadmin-[INFO]:-Starting gppkg with args: -i postgis-ossv2.0.3_pv2.0.1_gpdb4.3orca-rhel5-x86_64.gppkg
20160919:13:21:20:024675 gppkg:s-md-pv-gp-01-01:gpadmin-[CRITICAL]:-gppkg failed. (Reason='__init__() got an unexpected keyword argument 'postupdate'') exiting...

We've also run gppkg passing the -u flag, with similar results:

gppkg -u postgis-ossv2.0.3_pv2.0.1_gpdb4.3orca-rhel5-x86_64.gppkg 
20160919:13:35:52:024930 gppkg:s-md-pv-gp-01-01:gpadmin-[INFO]:-Starting gppkg with args: -u postgis-ossv2.0.3_pv2.0.1_gpdb4.3orca-rhel5-x86_64.gppkg
20160919:13:35:52:024930 gppkg:s-md-pv-gp-01-01:gpadmin-[WARNING]:-WARNING: The process of updating a package includes removing all
20160919:13:35:52:024930 gppkg:s-md-pv-gp-01-01:gpadmin-[WARNING]:-previous versions of the system objects related to the package. For
20160919:13:35:52:024930 gppkg:s-md-pv-gp-01-01:gpadmin-[WARNING]:-example, previous versions of shared libraries are removed.
20160919:13:35:52:024930 gppkg:s-md-pv-gp-01-01:gpadmin-[WARNING]:-After the update process, a database function will fail when it is
20160919:13:35:52:024930 gppkg:s-md-pv-gp-01-01:gpadmin-[WARNING]:-called if the function references a package file that has been removed.
Do you still want to continue ? Yy|Nn (default=N):
> y
20160919:13:35:59:024930 gppkg:s-md-pv-gp-01-01:gpadmin-[CRITICAL]:-gppkg failed. (Reason='__init__() got an unexpected keyword argument 'postupdate'') exiting...

A major caveat may also be related to the fact that only Greenplum versions 4.2.6.X to 4.2.8.X support both version 1.4 and 2.0 of postGIS. At this point, we're looking for some direction on how to proceed in hopes others may have come up against some of these hurdles.

We've got tickets in with the vendor, Pivotal, but these are not proving fruitful so I'm posting here in hopes the community has some direction they can point me in.

Thanks,

John