The Git suite CodingGuidelines suggest [this](https://github.com/git/git/blob/v2.26.2/Documentation/CodingGuidelines#L496) about Error messages: > Error Messages > - Do not end error messages with a full stop. > > - Do not capitalize ("unable to open %s", not "Unable to open %s") > > - Say what the error is first ("cannot open %s", not "%s: cannot open") There are various instances of violation of these rules, for instance [here](https://github.com/git/git/blob/v2.26.2/builtin/add.c#L281) and [here]((https://github.com/git/git/blob/v2.26.2/builtin/submodule--helper.c#L1220)). These violations need to be amended.