BOSS algorithm

I feed the BOSS() with a continuous dataset and get the following error message about singular matrix, is this expected?

Traceback (most recent call last):
  File "/home/min/a/lee4094/projects/bayesian_rcd/experiment_sockshop.py", line 203, in <module>
    cpdag  = boss(df_n_without_time.to_numpy(), score_func='local_score_BIC')
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/min/a/lee4094/miniconda3/envs/bayes_rcd/lib/python3.11/site-packages/causallearn/search/PermutationBased/BOSS.py", line 145, in boss
    gsts[v].trace(order[:i], parents[v])
  File "/home/min/a/lee4094/miniconda3/envs/bayes_rcd/lib/python3.11/site-packages/causallearn/search/PermutationBased/gst.py", line 69, in trace
    return self.root.trace(prefix, available, parents)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/min/a/lee4094/miniconda3/envs/bayes_rcd/lib/python3.11/site-packages/causallearn/search/PermutationBased/gst.py", line 44, in trace
    if self.branches is None: self.grow(available, parents)
                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/min/a/lee4094/miniconda3/envs/bayes_rcd/lib/python3.11/site-packages/causallearn/search/PermutationBased/gst.py", line 20, in grow
    score = -self.tree.score.score_nocache(self.tree.vertex, parents)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/min/a/lee4094/miniconda3/envs/bayes_rcd/lib/python3.11/site-packages/causallearn/score/LocalScoreFunctionClass.py", line 52, in score_nocache
    return self.local_score_fun((self.cov, self.n), i, PAi, self.parameters)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/min/a/lee4094/miniconda3/envs/bayes_rcd/lib/python3.11/site-packages/causallearn/score/LocalScoreFunction.py", line 73, in local_score_BIC_from_cov
    H = np.log(cov[i, i] - yX @ np.linalg.inv(XX) @ yX.T)
                                ^^^^^^^^^^^^^^^^^
  File "/home/min/a/lee4094/miniconda3/envs/bayes_rcd/lib/python3.11/site-packages/numpy/linalg/linalg.py", line 561, in inv
    ainv = _umath_linalg.inv(a, signature=signature, extobj=extobj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/min/a/lee4094/miniconda3/envs/bayes_rcd/lib/python3.11/site-packages/numpy/linalg/linalg.py", line 112, in _raise_linalgerror_singular
    raise LinAlgError("Singular matrix")
numpy.linalg.LinAlgError: Singular matrix

Start by reproducing the reported BOSS call from causallearn/search/PermutationBased/BOSS.py, then trace the failure through causallearn/search/PermutationBased/gst.py and causallearn/score/LocalScoreFunction.py. Check the continuous dataset and covariance inputs around local_score_BIC_from_cov; done means determining whether the singular matrix is expected and documenting or addressing the confirmed cause.