anchor.diff:  
   args: ~s
   
  -You have passed a cube-map texture without an attachment number, this
  -means you want the fbo to have 6 color attachments which are bound the
  +You have passed a cube-map texture without an attachment number; this
  +means you want the fbo to have 6 color attachments which are bound to the
   faces of the cube texture.
   
  -Whilst using this feature the only other legal argument is depth
  +Whilst using this feature, the only other legal argument is depth
   attachment info.
   " args)
   
  
positive.code:   type-name)
  
  (deferror buffer-backed-texture-invalid-args () ()
      "CEPL - make-texture: Buffer-backed textures cannot have mipmaps, multiple layers or be cube rectangle or multisample")
  
  (deferror buffer-backed-texture-invalid-samplers () ()
      "CEPL - make-texture: We do not currently support setting any texture sampling parameters on buffer backed textures")
  
  (deferror buffer-backed-texture-invalid-image-format () (type-name)
      "CEPL - make-texture: The internal format ~a is invalid for use with buffer-backed-textures"
  
negative.code:   (let ((unknown-keys (remove-if (lambda (x) (member x varjo:*stage-types*))
                                   keys)))
      (if unknown-keys
          (format nil "The following stages are not supported, or are incorrectly named: ~a"
                  unknown-keys)
          (format nil "The order of the following stages is incorrect:~%~s~%Valid order of stages is: ~a"
                  keys varjo:*stage-types*))))
  
  (deferror invalid-compose-gpipe-form () (pipeline-name clauses)
  