With the recent adoption of tomli as PEP680 tomllib, the toml package (which supports only TOML v0.5.0) used to verify syntactic correctness of toml files should be seen as deprecated. In #608 a switch to tomli was rejected, however given that the situation for toml has not improved since then, the pre-commit-hooks should switch as well. Alternatively the project could switch to rtoml which also supports newer versions of the TOML standard.