I am not sure if this is a bug or not. But, I have noticed some Hall symbols in spg_database.c differ from the list of Hall symbols in International Tables for Crystallography Vol. B (ITB).

In spglib, the so-called "V entry" in Hall symbols is not consistent with ITB: For example, in Table A1.4.2.7 of ITB, No. 151 is represented as P 31 2 (0 0 4). On the other hand, spg_database.c represents it as P 31 2c (0 0 1).