   githubGet "/repos/#{repo}/git/commits/#{sha}", token, callback
 
 processGraphsTree = (tree, objects, prefix) ->
+  return unless tree
   graphs = tree.tree.filter (entry) ->
     return false unless entry.type is 'blob'
     return false unless entry.path.match '.*\.(fbp|json)$'

    entry

processComponentsTree = (tree, objects, prefix) ->
  components = tree.tree.filter (entry) ->
    return false unless entry.type is 'blob'
    return false unless entry.path.match '.*\.(coffee|js|hpp|c|py)$'

    entry

processSpecsTree = (tree, objects, prefix) ->
  return unless tree
  specs = tree.tree.filter (entry) ->
    return false unless entry.type is 'blob'
    return false unless entry.path.match '.*\.(yaml|coffee)$'
