More comptime

We used a hard-coded ErrorColor when printing errors in the message area, time to change it in errorMessage():

    const fmt = ansi.ErrorColor ++ format ++ ansi.ResetColors;

    const fmt = comptime t.HlGroup.attr(.err) ++ format ++ ansi.ResetColors;

You should now delete the ErrorColor constant from ansi.

Note the comptime keyword here. Without it, the compiler would say:

error: unable to resolve comptime value
note: slice being concatenated must be comptime-known

With the comptime keyword, you force the compiler to at least try to get that value at compile time. In this case, it succeeds. Also note that comptime can precede any expression, to force it being evaluated at compile time: function calls, assignments, etc.

Again: you generally don't need the compile keyword. But if the compiler complains with that sort of errors, and you think it should be able to get the value, it's worth a try.