Follow ERP5 way of commit selection.

software/vifib/software.cfg

@@ -21,8 +21,10 @@ recipe = plone.recipe.command
 location = ${buildout:parts-directory}/${:_buildout_section_name_}
 stop-on-error = true
 repository = http://git.erp5.org/repos/slapos.core.git
-command = ${git:location}/bin/git clone --quiet ${:repository} ${:location}
-update-command = cd ${:location} && ${git:location}/bin/git pull --quiet
+branch = master
+revision =
+command = ${git:location}/bin/git clone --quiet -b ${:branch} ${:repository} ${:location} && if [ -n ${:revision} ]; then cd ${:location} && ${git:location}/bin/git reset --quiet --hard ${:revision} ; fi
+update-command = cd ${:location} && ${git:location}/bin/git pull --quiet && if [ -n ${:revision} ]; then cd ${:location} && ${git:location}/bin/git reset --quiet --hard ${:revision} ; fi
 
 [products]
 # XXX: Lack of eggification workaround