Traceback (most recent call last):


 "<stdin>", line 2, in <module>


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/skopt/optimizer/optimizer.py", line 417, in ask

opt._tell(x, y_lie)


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/skopt/optimizer/optimizer.py", line 536, in _tell

est.fit(self.space.transform(self.Xi), self.yi)


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/skopt/learning/gaussian_process/gpr.py", line 195, in fit

super(GaussianProcessRegressor, self).fit(X, y)


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/sklearn/gaussian_process/_gpr.py", line 235, in fit

optima = [(self._constrained_optimization(obj_func,


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/sklearn/gaussian_process/_gpr.py", line 506, in _constrained_optimization

opt_res = scipy.optimize.minimize(


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/scipy/optimize/_minimize.py", line 619, in minimize

return _minimize_lbfgsb(fun, x0, args, jac, bounds,


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/scipy/optimize/lbfgsb.py", line 306, in _minimize_lbfgsb

sf = _prepare_scalar_function(fun, x0, jac=jac, args=args, epsilon=eps,


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/scipy/optimize/optimize.py", line 261, in _prepare_scalar_function

sf = ScalarFunction(fun, x0, args, grad, hess,


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/scipy/optimize/_differentiable_functions.py", line 136, in __init__

self._update_fun()


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/scipy/optimize/_differentiable_functions.py", line 226, in _update_fun

self._update_fun_impl()


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/scipy/optimize/_differentiable_functions.py", line 133, in update_fun

self.f = fun_wrapped(self.x)


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/scipy/optimize/_differentiable_functions.py", line 130, in fun_wrapped

return fun(x, *args)


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/scipy/optimize/optimize.py", line 74, in __call__

self._compute_if_needed(x, *args)


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/scipy/optimize/optimize.py", line 68, in _compute_if_needed

fg = self.fun(x, *args)


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/sklearn/gaussian_process/_gpr.py", line 227, in obj_func

lml, grad = self.log_marginal_likelihood(


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/sklearn/gaussian_process/_gpr.py", line 481, in log_marginal_likelihood

alpha = cho_solve((L, True), y_train)
# Line 3


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/scipy/linalg/decomp_cholesky.py", line 194, in cho_solve

b1 = asarray_chkfinite(b)


 "/home/aschilperoort/test/venv/lib/python3.8/site-packages/numpy/lib/function_base.py", line 488, in asarray_chkfinite

raise ValueError(
ValueError: array must not contain infs or NaNs

[E 2020-07-29 11:50:45.314 SingleUserNotebookApp handlers:179] Traceback (most recent call last):


 "/usr/local/lib/python3.7/dist-packages/nbgrader/server_extensions/course_list/handlers.py", line 172, in get

local_courses = yield self.check_for_local_formgrader(config)


 "/usr/local/lib/python3.7/dist-packages/tornado/gen.py", line 735, in run

value = future.result()


 "/usr/local/lib/python3.7/dist-packages/tornado/gen.py", line 742, in run

yielded = self.gen.throw(*exc_info)
# type: ignore


 "/usr/local/lib/python3.7/dist-packages/nbgrader/server_extensions/course_list/handlers.py", line 63, in check_for_local_formgrader

response = yield http_client.fetch(url, headers=header)


 "/usr/local/lib/python3.7/dist-packages/tornado/gen.py", line 735, in run

value = future.result()

ConnectionRefusedError: [Errno 111] Connection refused
```
