While we're on a roll lately discussing programming questions and what should or shouldn't be asked on this site, I figured we might as well go all the way and take a more definite decision about close reasons and migrations.
The issue of setting up a migration path to StackOverflow was discussed some time ago in Add stackoverflow to the "belongs on another site in the SE network" closing option, and mentioned again recently. The more general question of whether/which questions should be allowed here, and which ones are more suited for StackOverflow, was previously discussed e.g. in When and why should we close a question for being more appropriate on Stack Overflow? and more recently in Would it make sense for there to be a separate SE site for "quantum programming" or "quantum information software", versus quantum information theory?.
However, setting up migration paths, or more generally encouraging migration towards StackOverflow or elsewhere, might not be the best course of action (I'm not saying we shouldn't do it, only that the decision is not as straightforward as it might appear). Here are two ways of handling the matter that come to mind:
Setting up a migration path. To this end, it's worth noting that it's not a given that we can even do it. Default migration paths can only be set by Staff members, and it doesn't seem straightforward to have a request approved. See e.g. When should we consider adding a default migration path?, A proposed philosophy of question migration, and discussions therein. Quoting Shog9 from the former link:
[When should we consider adding a default migration path?] Almost never. These paths have a place when two conditions exist:
- There is a clearly-defined topic that is wholly inappropriate on one site and wholly appropriate on another.
- That topic is asked about daily on the former site.
This is pretty rare. Especially if the first site isn't Stack Overflow
Truth is, migrations are not often particularly necessary. It's usually just as easy for the asker to re-post his question on a new site as it is for 5 close-voters or a moderator to migrate. There are better tools available for those rare occasions when a new site is actually carved off of an existing one, and that's primarily what the current system was designed to handle anyway!
If we really wanted to make this work, we'd consider either folding migrations into site-specific off-topic reasons or separating it from closing entirely, as an alternative to deletion. Although there are some other ideas floating around too.
Now, the above criteria are at least partially fulfilled for pure programming questions here, though I suppose whether these are "wholly inappropriate" on this site might be subjective.
An important point to keep in mind is, however, that migrations should not be used to send away "bad" questions. Questions that probably will get closed on the target site as well, should not be migrated. This raises the issue that we should have a good idea of how questions would get received on the target site. This also means that migrations should arguably mostly be handled by people who are active on the target site, and thus have a good idea of what might be accepted or not. For a recent example, consider this question. Should this be migrated on SO? To me, it seems likely that it misses details and context, and is overspecific, and thus might get closed on SO as well. Then again, I'm not 100% positive about it. So is it better to migrate it, or to just close it here as OT, and leaving the choice to reask on SO to the OP?
This brings me to another possible solution. Rather than (attempting to) set up a migration path to SO, we could make a new custom close reason here. Something along the lines of (I'm shamelessly copying parts of Adam Zalcman's stub for the programming tag here):
This question appears to be a pure programming question. While programming questions are not off-topic per se, questions on this site should involve some knowledge of quantum computation or quantum information. Pure programming questions, including those concerning quantum computing software frameworks or cloud services, should be asked on StackOverflow.
This clearly tells the user what types of questions are accepted, and suggests that their question might be better received on StackOverflow, but relieves us from the burden of having to decide whether the question will get closed on SO.
We could also set up a meta post to link in there, giving examples and being more explicit about the criteria determining which questions are on-topic on this site.
One thing to keep in mind here is that there is a limited number of custom close reasons we can add. There is currently only one additional spot left, so adding this one we are using all available custom close reasons. It is possible to get more, but we'd need to ask CMs to do it, and we'd likely need to have a good reason for doing so (I don't predict this to be a problem, I just mention it as an FYI).
Just as a final remark and FYI, mods can always migrate any question to any target site. This means that for edge cases, you can always flag for mod attention arguing where and why the question should be migrated. The downside of this is that we cannot start a close vote to migrate the question: we either decide to close/migrate it, or not. In some cases the best course of action is obvious, but in other cases, it might not be, and then we might choose to act conservatively and not migrate (although obviously, this will depend on the specific case and person handling it). We can ping the moderators on the target site to ask their opinion and decide based on that, but this is only fine for sporadic occurrences.
I'm personally leaning towards the second option above. What do you think we should do?
PS: As you might or might not have noticed, I recently migrated this question to SO. The reason is that I was trying to figure out how to set up new migration paths, and because I couldn't find the option anywhere, I figured maybe there would be a checkmark to set the default migration path while migrating the question or something like that. Alas, that was not the case, sorry about that. I then realised the reason I couldn't figure it out is that it can only be done by Staff. To experiment, I chose a question that seemed like it would be better off on SO anyway, so hopefully, while not ideal, this isn't really a problem.