This is a one line recipe to allow buildout users to refer to ${grp:GROUP} to obtain the current user's UNIX group id. In other words, the results of:

$ id -g -n

on UNIX systems, for the user executing the buildout. This can be used with gocept.recipe.env and plone.recipe.command to configure ownership of the buildout directory, e.g.:

[env]
recipe = gocept.recipe.env

[grp]
recipe = collective.recipe.grp

[chown]
recipe = plone.recipe.command
command = chown -R  ${env:USER}:${grp:GROUP} ${buildout:directory}