message: Issue in numpy writeable flag. Could not reproduce TravisCI problem on local machine... Trying if copying the data array helps.
diff: @@ -206,8 +206,7 @@ class ACSF(Descriptor):
  dmat_secondary = dscribe.utils.geometry.get_adjacency_matrix(self.rcut, neigh_pos, neigh_pos)
  col = [neighbour_indices[x] for x in dmat_secondary.col] # Fix col numbering to refer to original system
  row = [neighbour_indices[x] for x in dmat_secondary.row] # Fix row numbering to refer to original system
  - data = dmat_secondary.data
  - dmat_lil[row, col] = data
  + dmat_lil[row, col] = np.array(dmat_secondary.data)
  # Get adjancency list and full dense adjancency matrix
  dmat = dmat_lil.tocoo()
  