Question: A few minutes ago, a [question about *"double compilation"*](https://stackoverflow.com/q/24965167/2344584) was posted. The OP read an article claiming that passing an already compiled executable through GCC for a second time results in a 2x speed boost and asked how that was possible.

Double compilation is clearly impossible and the article is likely to be a hoax. But I realize that it might not be obvious to newbies, so I am uncertain whether:

1. I should vote to close the question as off-topic for SO
2. the question should be left open for people to learn about the hoax.

So, should I vote to close the question or leave it open?

Answer: 
If such an article actually *exists*, then you should probably answer the question and point out why it's bunk (assuming it is).

If the article *doesn't* exist, then it's not a real question. Either close it as unclear and note that such an article should be linked to / cited so that folks can effectively answer the question, or close it as off-topic and write in something about pulling the one with bells on it.
It's a similar case to [Which is faster: while(1) or while(2)?](https://stackoverflow.com/questions/24848359/which-is-faster-while1-or-while2)

Such questions should exist on SO, just to provide the reference to the future visitors that it's a hoax. A hoax must be demented publicly, because otherwise anyone googling for that hoax would find only the sites that "prove" it. 

It's not hard to believe, even for an advanced programmer, that some tool may give better result when run second time. Unfortunately, the tools that give the other output each time they are run, or even are unable to run correctly at the first time, are getting more and more the normality.