i've just recently installed qgis 2.8.1 on my mac. including all relevant packages from kyngchaos - i.e. GDAL Complete 1.11 framework package, Matplotlib Python module, numpy - and updated python to 2.7.9
did some testing and was pretty happy with the new 2.8.1
when i tried to run gdal/ogr geoalgorithms from processing toolbox qgis returned the following error: "GDAL command output: /bin/sh: xxx: command not found" ... where xxx is the name of the command.
same problem with any tested command !
i've already been searching for that kind of issue for a while but didn't find anything that could solve the problem. most promising was an article about inserting /Library/Python/2.7/site-packages - path into sys.path ... but nothing changed.