[users at bb.net] Github Merge Refs is "Undocumented Feature"

[David Alves]

Hi

  I've seen sporadic build issues when pushing a new rev of a 
  GitHub pull request
  because buildbot pulls the merge ref and the merge ref is often 
  not immediately updated.
  This causes the build triggered by the updated rev to actually 
  use the merge ref
  corresponding to the previous rev, making the results of the 
  build unreliable without
  re-checking that the correct code was actually tested.
  When contacted about this Github claimed merge refs are an 
  undocumented feature and
  that they don't advise to use them.
  The alternative seems to be building from the head ref instead 
  of the merge ref.
  IMO this makes sense. Would you be open to patch to fix this?

Best
--
David Alves