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Comment by tikhonj

9 hours ago

There is a pretty clear and important difference between a program that does something wrong, and a program that just doesn't do something somebody wants.

"You don't support printing", "pressing the print button doesn't print", "pressing the print button crashes the computer" and "pressing the print button lets an attacker get root access to the system" are all different and it makes sense to distinguish them. (The first is a missing feature, the second and third are different kinds of bugs, the last is a special kind of bug we call a security vulnerability.)

That distinction might not be useful to end-users, but it's useful for the people building the system! If you want to care about quality, committing to a strategy like "we will not add features before we fix known bugs" is totally clear, reasonable and effective. There might be some frontier of issues where it's hard to make a distinction, but that just means there are subtle edge-cases, not that the whole concept is undefined. A lot of perfectly cromulent concepts have edge-cases! You can just decide those on a case-by-case basis; if it's actually so close as to be legitimately confusing—it's not just feigned ignorance or political posturing—which side you choose probably doesn't have much of an effect.

This does depend on having a reasonably clear idea of what you're building, but that "reasonably clear idea" does not have to be anywhere near the detail of a "full spec", much less anything formalized. To me, that seems like a baseline you'd need to build quality software at all, and hardly an unreasonable thing to expect. And if most teams can't manage, well, it's just another explanation for why most software is crap.

> There is a pretty clear and important difference between a program that does something wrong, and a program that just doesn't do something somebody wants.

Your argument hinges on all parties agreeing on what "wrong" means. Take a step back and consider that parties do not agree on a common definition of "wrong." Does "wrong" mean a gap between the spec and the implementation or a gap between a reasonable user's expectation and the implementation? If one party assert that it is clearly the former and the other party asserts it is clearly the latter, does that make the situation more clear or less clear?

  • Just because you can't get everyone to agree does not mean that the concept is not well-defined or clear. People can and do disagree over almost anything. That could just mean that one side is wrong and the other side is right, even if it is difficult to determine which is which... or simply difficult to navigate the underlying politics regardless.

    Besides, in your example, either kind of gap could be a bug or a missing feature. It's a totally orthogonal question.

  • There are some really obvious things that are definitely bugs. If login doesn’t work if your email address contains the letter “e” when the expectation is all valid email addresses should work, then that is a bug. It isn’t “indistinguishable from a feature”. If clicking a button in your accounting software consumes all the RAM on your computer and causes it to crash, then there is no universe or agreed upon definition that would consider that a feature instead of a bug.

    • >If login doesn’t work if your email address contains the letter “e” when the expectation is all valid email addresses should work,

      And what about the + symbol?

  • >Your argument hinges on all parties agreeing on what "wrong" means

    No, it just hinges on common sense. "All parties" are never gonna agree on everything.

    There will always be customers that demand whatever and treats its lack as a bug. Doesn't make it a bug anymore than me asking for a free glass of wine with my meal and not being given any is "injustice" - when the restaurant never promised any.