stack trace of error

stacktrace.txt

(bayesopt) Michaels-MacBook-Pro-2:release_pre_alpha curry$ python run_stybtang_transform.py 
[array([2, 4, 9]), array([8]), array([6, 7, 5]), array([1, 3, 0])]
Running Multi MCMC model selection BO on rotated Stybtang
12.3249773332
141.004751431
 /Users/curry/src/GPy/GPy/kern/src/rbf.py:43: RuntimeWarning:overflow encountered in square
 /Users/curry/src/GPy/GPy/kern/src/stationary.py:167: RuntimeWarning:overflow encountered in divide
 /Users/curry/src/GPy/GPy/kern/src/rbf.py:46: RuntimeWarning:invalid value encountered in multiply
 /Users/curry/anaconda3/envs/bayesopt/lib/python2.7/site-packages/paramz/transformations.py:108: RuntimeWarning:invalid value encountered in greater
 /Users/curry/anaconda3/envs/bayesopt/lib/python2.7/site-packages/paramz/transformations.py:113: RuntimeWarning:invalid value encountered in greater
Traceback (most recent call last):
  File "run_stybtang_transform.py", line 80, in <module>
    bo_model.initialize_run()
  File "/Users/curry/Desktop/release_pre_alpha/bayes_opt.py", line 56, in initialize_run
    self.model.optimize()
  File "/Users/curry/src/GPy/GPy/core/gp.py", line 627, in optimize
    ret = super(GP, self).optimize(optimizer, start, messages, max_iters, ipython_notebook, clear_after_finish, **kwargs)
  File "/Users/curry/anaconda3/envs/bayesopt/lib/python2.7/site-packages/paramz/model.py", line 115, in optimize
    self.optimizer_array = opt.x_opt
  File "/Users/curry/anaconda3/envs/bayesopt/lib/python2.7/site-packages/paramz/parameterized.py", line 336, in __setattr__
    return object.__setattr__(self, name, val);
  File "/Users/curry/anaconda3/envs/bayesopt/lib/python2.7/site-packages/paramz/core/parameter_core.py", line 118, in optimizer_array
    self.trigger_update()
  File "/Users/curry/anaconda3/envs/bayesopt/lib/python2.7/site-packages/paramz/core/updateable.py", line 79, in trigger_update
    self._trigger_params_changed(trigger_parent)
  File "/Users/curry/anaconda3/envs/bayesopt/lib/python2.7/site-packages/paramz/core/parameter_core.py", line 128, in _trigger_params_changed
    self.notify_observers(None, None if trigger_parent else -np.inf)
  File "/Users/curry/anaconda3/envs/bayesopt/lib/python2.7/site-packages/paramz/core/observable.py", line 91, in notify_observers
    [callble(self, which=which) for _, _, callble in self.observers]
  File "/Users/curry/anaconda3/envs/bayesopt/lib/python2.7/site-packages/paramz/core/parameter_core.py", line 498, in _parameters_changed_notification
    self.parameters_changed()
  File "/Users/curry/src/GPy/GPy/core/gp.py", line 255, in parameters_changed
    self.posterior, self._log_marginal_likelihood, self.grad_dict = self.inference_method.inference(self.kern, self.X, self.likelihood, self.Y_normalized, self.mean_function, self.Y_metadata)
  File "/Users/curry/src/GPy/GPy/inference/latent_function_inference/exact_gaussian_inference.py", line 50, in inference
    Wi, LW, LWi, W_logdet = pdinv(Ky)
  File "/Users/curry/src/GPy/GPy/util/linalg.py", line 204, in pdinv
    L = jitchol(A, *args)
  File "/Users/curry/src/GPy/GPy/util/linalg.py", line 72, in jitchol
    raise linalg.LinAlgError("not positive definite, even with jitter.")
numpy.linalg.linalg.LinAlgError: not positive definite, even with jitter.