mapnik configure fails during rpmbuild, but succeeds manually - awk

Question

I've posted this issue on the google groups area for mapnik already, so I'm just going to c/p from there:
I've been troubleshooting this issue for a couple days, now. Bear with me for context:
Starting from a freshly-untarred source of mapnik 2.2.0 on RHEL 6.5:
First off, running "./configure" (which just calls scons/scons.py) works great. Finishes correctly, then I run make + make install and I get exactly what I want built and installed.
My goal has been to create a mapnik 2.2.0 RPM for internal use. Please do not suggest using an "official" mapnik RPM instead (or any other already-built mapnik RPM), as my entire purpose here is to build mapnik from source and create my own RPM.
That being said, when my RPM gets to its %build phase and runs ./configure, it freezes while scons checks for freetype-config. I've let it sit for hours, and nothing happens.
After I looked at the generated config.log file, it would appear that configure is failing on an "awk" command that goes something like this:
awk '{print $\(NF-1\)}'
The command is performed on the string that results from the command:
/usr/bin/freetype-config --libs --cflags
I'm wondering, first of all, how to fix this, but second of all why this would work manually, but fail when the rpmbuild process gets to the ./configure command. I've made sure that the same user (myself) is running both ./configure commands on the exact same files.
My third question would be: why does the configure step freeze on this issue, instead of throwing some sort of error and stopping?
Note that the problem with the "awk" command is the backslashes--the error is:
awk: {print $\(NF-1\)}
^ backslash not last character on line
When I remove the backslashes, the command succeeds. Whether or not removing the backslashes is the correct thing to do in the long run, I do not know.
It would seem this is some sort of python string-parsing / encoding issue, but I'm unsure. What really confuses me is why this works manually and fails when the rpmbuild tries to do it.
My only thought is that there's some difference between the rpmbuild environment and my shell that I configured on. What it is, I do not know.
Thank you for any assistance you can provide. If I can provide any more context, please let me know.
UPDATE: an svn command runs after the awk failure, but is missing whatever number gets passed after the -r option. I'm wondering if this could be causing the hang...thoughts?