I've just installed QGIS 2.6 Brighton using the OSGeo4W installation. The GRASS toolbox plugin has not, however installed as it had been with previous versions. Before, I was able to access the GRASS Tools via the tab Vector > GRASS, but it is now absent. Is this a change in the software or due to an error in the installation? If so, how can I rectify this issue?
Re-run the setup, change to
advanced install and look if the package
grass is selected. It should be selected automatically as dependency.
If it is, look under
Processing -> Options -> Dataproviders -> GRASS commands. The first item should be checked.
Finally, make sure to switch to
advanced interface at the bottom of the processing toolbox. You should see 168 geoalgorithms available for GRASS.
BTW, GRASS has been part of Sextante/Processing for quite some time now (at least since QGIS 1.8).