Using that model, we can prove conclusively that, since a behavior has changed (a warning printed), it might cause problems. Therefore, we cannot prove that it cannot cause problems. What we would really like, though, is an actual problem shown to exist. Just like in mathematics; it’s one thing to prove that it’s impossible to prove something could not exist, but another thing entirely to show it existing.
You are overlooking something here: I never said anything about proof. I explicitly wrote 'convincing evidence' because proof is too demanding!
It's rather amusing how you have flipped from saying "you can't prove a negative" to an argument for the certainty of observable effects and the probability of consequences! (you wrote might cause problems, but everyone can see that's an unrealistic understatement of the implications of the argument you are using.)
The NASA managers prior to the Challenger crash thought that what they really wanted was something showing them an actual problem existed. Erring on the side of caution is generally prudent, even in relatively small matters.
> everyone can see that's an unrealistic understatement of the implications of the argument you are using
If nobody can show an actual existing problem, or even an example of reasonable code someone could have written which would be impacted by a the printed warning, then yes, I would think that I was charitable when I wrote “might cause problems”.
What does 'charitable' mean here? Generous towards what person or point of view? As you say you have conclusively proved that there is a non-zero probability of there being problems, the use of 'might' is already trying to persuade that this possibility is next to zero.
Yes, of course. If the case is reasonably likely to occur in the real world and have real world impact, that is. And I would assume that the GNU grep developers would agree with me.
I think that is a very reasonable position to hold. It would only be the rejection of plausible cases, on the basis of no actual case having been uncovered, that I would take issue with. When assessing the downside of a proposal, there should not be much, if any, difference between how highly plausible and certain consequences are assessed.
If we could prove there would be no downside, then plausible problems could be ignored as merely hypothetical, and there would be no need to posit offsetting benefits. The question the GNU grep developers might want to consider is whether the supposed upside will have sufficient material consequences for their purposes.
