I just did a fresh install of QGIS 2.10.1 from the qgis repos (Ubuntu 14.04). I also have grass70 installed (through ubuntugis-unstable).
I can see the GRASS7 commands in the processing toolbox panel, but when I try to use them I got the Missing dependency. This algorithm cannot be run :-( message.
In the plugins log I noticed that QGIS could not load
libgrassplugin6.so, but I'm guessing that is not the issue since I'm trying to run grass7 algorithms.
Also, on the processing log I got this output when trying to run a grass 7 command:
GRASS GIS 7 execution commands g.proj -c proj4="+proj=utm +zone=30 +ellps=intl +towgs84=-87,-98,-121,0,0,0,0 +units=m +no_defs" v.in.ogr min_area=0.0001 snap=-1 input="/usr/share/qgis/python/plugins/processing/tests/data" layer=points output=tmp1444494282425 --overwrite -o g.region -a n=4458983.8488 s=4458921.97814 e=270855.745301 w=270778.60198 res=100 v.voronoi input=tmp1444494282425 output=output22e863becb734ae4a06720411090abf0 --overwrite v.out.ogr -s -e input=output22e863becb734ae4a06720411090abf0 type=auto output="/tmp/processing/b5eb2443ef0840239dc22209a29a71db" format=ESRI_Shapefile olayer=output
But when I try to run a GRASS command (without version, I think that means grass 6, doesn't it?), I got no output on the log. I think that must mean something.
I started QGIS from a console and got this error when I try to execute a GRASS 7 algorithm:
ERROR 4: Unable to open /usr/share/qgis/python/plugins/processing/tests/data/points.shp or /usr/share/qgis/python/plugins/processing/tests/data/points.SHP.
At first I thought it was a permissions issue (the file exists), so i chmod it to 777 but the error persisted.
Browsing around the processing plugin code, it seems that every time you run a grass algorithm the plugin runs a test using that file.