env MPICC=/comm/swstack/core/intel-2019.5.281/mpich/3.2/bin/mpicc pip install mpi4py==3.0.1
pip install cymem==1.31.2

    def get_new_candidate(self, parents):
        """Generate new candidate by applying a randomly drawn
        operation on the structures. This is done successively for
        each list of operations, if multiple are present.
        """
        for op_list, rho_list in zip(self.operations, self.rho):
            for i_trial in range(5): # Do five trials
                to_use = self.__get_index__(rho_list)
                anew = op_list[to_use].get_new_candidate(parents)
                if anew is not None:
                    parents[0] = anew # anew will be used in next set of operations
                    break
            else:
                anew = parents[0] # use old parents[0] if the operation failed
                anew = op_list[to_use].finalize(anew, successfull=False)
        return anew

Traceback (most recent call last):
  File "calc_gofee.py", line 62, in <module>
    search.run()
  File "/home/tang/project/constrained-GOFEE/src/gofee/gofee.py", line 295, in run
    unrelaxed_candidates = self.generate_new_candidates()
  File "/home/tang/project/constrained-GOFEE/src/gofee/gofee.py", line 372, in generate_new_candidates
    candidates = parallel_function_eval(self.comm, func1)
  File "/home/tang/project/constrained-GOFEE/src/gofee/parallel_utils.py", line 21, in parallel_function_eval
    results = func()
  File "/home/tang/project/constrained-GOFEE/src/gofee/gofee.py", line 371, in func1
    return [self.generate_candidate() for i in task_split[self.comm.rank]]
  File "/home/tang/project/constrained-GOFEE/src/gofee/gofee.py", line 371, in <listcomp>
    return [self.generate_candidate() for i in task_split[self.comm.rank]]
  File "/home/tang/project/constrained-GOFEE/src/gofee/gofee.py", line 394, in generate_candidate
    parents = self.population.get_structure_pair()
  File "/home/tang/project/constrained-GOFEE/src/gofee/population.py", line 97, in get_structure_pair
    t1, t2 = np.random.permutation(len(self.pop))[:2]
ValueError: not enough values to unpack (expected 2, got 1)

def get_structure_pair(self):
    t1, t2 = np.random.permutation(len(self.pop))[:2]
    structure_pair = [self.pop[t1].copy(), self.pop[t2].copy()]
    return structure_pair

def get_structure_pair(self):
    try:
        t1, t2 = np.random.permutation(len(self.pop))[:2]
    except ValueError:
        t1 = 0
        t2 = 0
        print('len(self.pop): {}'.format(len(self.pop)))
        print(self.pop)
    structure_pair = [self.pop[t1].copy(), self.pop[t2].copy()]
    return structure_pair