You've got more than 10 bugs. You just don't know it yet.
But really, "bug tracker" is just a colloquial expression for the more accurate "issue tracker" which can definitely include things like improvements, new features, A/B tests you want to run, etc.
Where can one get a job as a professional FizzBuzz developer?
I think if a program is big enough to devote a software developer to it full-time, it's going to have at least 10 bugs. Maybe they are small or unimportant or so obscure that none of the users actually run into it, but they're in there somewhere.
But really, "bug tracker" is just a colloquial expression for the more accurate "issue tracker" which can definitely include things like improvements, new features, A/B tests you want to run, etc.