Having trouble installing ofxGStreamer - ofGstUtils.cpp not found (partial fix)

I’m having some trouble getting ofxGStreamer to work. I followed arturo’s instructions exactly as outlined here: https://github.com/arturoc/ofxGStreamer and then I created a project using the Project Generator and added the ofxGStreamer addon.

When I try to compile the generated project in XCode I get the following error: 'No such file or directory: ‘/libs/openFrameworks/video/ofGstUtils.cpp’.

Even though if I check this folder: /of_v0.9.8_osx_release/libs/openFrameworks/video/ , ofGstUtils.cpp is right there.

If I navigate to that same folder in the Project navigator on XCode I can also see the ofGstUtils.cpp file under video.

I’m using:
-OSX Sierra 10.12.3
-Open Frameworks 0.9.8
-XCode 8.3.3

Any advice on what to try?

Update: I see some connection to this post, which leads me to think the problem lies with addon_config.mk not setting my addon_sources right. I think it has to do with the fact that $(OF_ROOT) is pointing to something incorrect.

I changed my ../addons/ofxGStreamer/addon_config.mk file and replaced all the $(OF_ROOT) declarations with the full local path to my openframeworks folder (i.e. /Users/user_name/Documents/of_v0.9.8_osx_release/) and it worked. Obviously this is just a solution on my local computer. What would be the right way to fix this more generally?