Calling xdc build commands from Python

Our automated build process is built around Python, and I am having difficulty getting the xdc command to be run by the python environment. Some modules it can build, but our custom HPI driver has an issue finding a module. This process works from the normal command line. Below is the xdc output with some debug output options enabled.

call: xdc all -Pr /home/home_dir/p4/tidsp/src_rtsc

making all: Fri Sep 2 13:07:25 EDT 2011 ...
======== .interfaces [/home/home_dir/p4/tidsp/src_rtsc/common_repo/constants] ========
gmake[1]: `.interfaces' is up to date.
======== .interfaces [/home/home_dir/p4/tidsp/src_rtsc/common_repo/drivers] ========
#
# generating interfaces for package common_repo.drivers (because package/package.xdc.inc is older than package.xdc) ...
/home/home_dir/p4/tidsp/ti_rtsc/lin/xdctools_3_22_01_21/xs -Dxdc.path="/home/home_dir/p4/tidsp/ti_rtsc/lin/xdctools_3_22_01_21/packages;/home/home_dir/p4/tidsp/ti_rtsc/bios_6_32_01_38/pacakges;/home/home_dir/p4/tidsp/ti_rtsc/ipc_1_23_01_26/packages;/home/home_dir/p4/tidsp/ti_rtsc/uia_1_00_01_16_eng/packages;/home/home_dir/p4/tidsp/ti_rtsc/lin/xdctools_3_22_01_21/packages;../.." -Dxdc.root=/home/home_dir/p4/tidsp/ti_rtsc/lin/xdctools_3_22_01_21 -Dxdc.hostOS=Linux -Dconfig.importPath=".;/home/home_dir/p4/tidsp/ti_rtsc/lin/xdctools_3_22_01_21/packages;/home/home_dir/p4/tidsp/ti_rtsc/bios_6_32_01_38/pacakges;/home/home_dir/p4/tidsp/ti_rtsc/ipc_1_23_01_26/packages;/home/home_dir/p4/tidsp/ti_rtsc/uia_1_00_01_16_eng/packages;/home/home_dir/p4/tidsp/ti_rtsc/lin/xdctools_3_22_01_21/packages;../..;/home/home_dir/p4/tidsp/ti_rtsc/lin/xdctools_3_22_01_21;/home/home_dir/p4/tidsp/ti_rtsc/lin/xdctools_3_22_01_21/etc" -Dxdc.bld.targets="" -DTOOLS=  -f xdc/services/intern/cmd/build.xs  -m package/package.xdc.dep -i package/package.xdc.inc package.xdc
    translating Hpi
"common_repo/drivers/Hpi.xdc", line 260:  can't resolve name (ti.sysbios.gates.GateHwi)
error:  compilation failed: parser failed
gmake[1]: *** [package/package.xdc.inc] Error 1
gmake: *** [/home/home_dir/p4/tidsp/src_rtsc/common_repo/drivers,.interfaces] Error 2

Near as I can tell the environment for the XDC call is setup properly, any ideas?

Thanks