PHP Errors Reference question [closed]

Question

I recently came across this question.

It basically boils down to

1. What is the cause of white screen?
2. What is the cause of X?
3. What is the cause of Y?

with each question being hyperlinked to an answer and the whole thing being community-wiki.

What's your thoughts on this question? Should we allow such things or should it be broken up more?

Answer 1

I think that we should not lose sight of the fact that we need to adapt as time marches on. The PHP tag is an angry, bloody mess. I think we also need to be happy that the tag has more or less permanent fixtures in the community that help keep it clean, and support them in their efforts. The question they created is a flare, it's a flare that says we just can't take this constant stream of crap anymore, give us something better to deal with it.

I am also part of that community. PHP is not my primary language, but I have to use it daily.

That being said, this illustrates a problem, people don't read tag wikis - yet doing so would save a lot of people a lot of time and trouble. Putting what they compiled into the tag wiki is like putting it in the attic and leaving a note on the back door to let people know it's there.

Sure, a little duplication is a very good thing because:

• People search for stuff differently
• The context of one question might be more interesting than another, resulting in even more information someone could walk away with
• Searches turn up more results eventually leading the searcher to what we (hope) is a well maintained question

That's the problem, when duplicates come in at the volume that PHP is seeing, we break away from useful and get into downright absurd.

This last attempt was noble, and took quite a bit of time to put together. Is it the answer? No. We can't close against a massive list of possible errors - because we'd then be effectively closing against answers on other questions instead of other specific questions. We're not set up to do that consistently, and the need for it is (while huge to the PHP community) relatively local in the grand scope of things.

That does not, however, excuse us from coming up with a better idea. All we've done to date is put every idea and effort they have come up with under extreme scrutiny, without offering up anything better. We complain when they get badges, we complain when they try to make sure that crap gets enough momentum to close and decay quickly, then we complain when they try to make encyclopedic references.

How much more effort are these people expected to put in? How much do they have to fight for it like C++ did to keep their book list?

We can do better than that, and we should.

Answer 2

I get the intent of the project, and the spirit in which it was created: the same questions keep coming up on Stack Overflow, and some people are sick of seeing them, so why not have one canonical reference so Stack Overflow's tubes don't get clogged or what-have-you?

The problem is that it's not realistic. Take a look at the question counts for some of the errors listed:

• Warning: Cannot modify header information - headers already sent: 416 (82 possible questions closed as dupes)
• Fatal error: Using $this when not in object context: 112 (no possible dupes found)
• T_PAAMAYIM_NEKUDOTAYIM: 80 (1 possible dupe)
• Call to member function on a non object: 56 (3 possible dupes)

Stack Overflow sucks at comprehensively closing commonly-asked questions as duplicates of previous questions. Creating yet another question and expecting that it's going to be used as a dupe target for all, even most, of the questions that ask about these errors is wishful thinking.

If this reference is useful to refer to, add it to a tag wiki. But if you want questions to use as dupe targets, look to the dozens of questions already asked and use one of them. If none of them have a good answer (something I find unlikely), add your own.

Also see: Dr. Strangedupe: Or, How I Learned to Stop Worrying and Love Duplication

Answer 3

Since this discussion led to Reference - What does this symbol mean in PHP? to be closed again, I'll throw in my 2c in as well.

When I created the Operator Reference more than two years ago, the same fuss happening right here happened there as well. The question would immediately gain a notable number of upvotes indicating interest, then a flood of comments came in (now deleted) complaining about it. The question got closed and reopened and closed and reopened. Almost all of the arguments I hear right now I heard back then.

Let's look at the facts for a few seconds.

• it is not a real question
• it is not constructive
• it is not how Questions are supposed to be used
• it should be a tag wiki

I give you that. It's all true. And for both References in question. So by that definition, they sure should be closed and deleted.

But, at least for the Operator Reference, it is also true that

• 832 upvotes and 606 favorites mean people apparently find it useful
• it currently ranks at #3 in the highest voted PHP questions
• it is actively used to close new Operator questions
• it solved the problem that you cannot search for Operators (no longer an issue)
• it is an exception to the rule

This is value!

I have no other numbers to back that, but my impression is that there is less new operator questions nowadays. And those new ones are closed against the Operator Reference, often with a specific question given as second dupe. Feel free to validate this claim.

Granted, this new Reference (not created, but supported by me) does not fix a shortcoming in SO's search engine However, given the vast amount of dupes we have about errors, warnings and notices, it doesn't matter that you can search for these. Because it is simply not expedient to go searching for these anymore.

Most of the existing questions are too localized and contain answers like "fix line 65". It is hard to find a suitable dupe among these because of the sheer amount of them. By the very same rules that got both References closed now, none of these other Questions should exist. But they do. They get answered over and over again. We are not closing them as too localized (well, I do) because they are easy reputation and not answering them would leave the OP with no solution whatsoever. So instead we pile up. Is that really the solution?

If this new Reference contains a general solution to common errors (not all, that's impossible) along with additional links to quality answer or existing Canonicals, we have a first line of defense against these questions. And we won't leave the OP in the rain. Yes, they still have to search the Reference then, but that is very little effort given that it is a) a filtered list b) containing relevant links and 3) the OP should have done so before asking anyway.

Even if we can't stop them from asking, maybe we can stop us from piling up.

Linking to References is not bad

One of the more common complaints here is that linking to a reference instead of a concrete question is bad. People won't find their answers in the Reference they say. I disagree, because people are not braindead. If anything they are too lazy to search. That's their own fault then. Nothing we can do will make them search. However, I wonder how you know that all the questions we closed against a real question actually did or didn't answer their problem at all?

I must have closed more than two thousand questions by now (most without the reference) and I can count the ones where an OP actually said "right, that solves it" on one hand. I got about three dozens cases where an OP complained that the dupe is not appropriate. The vast majority simply didn't say anything at all. They won't even upvote anything in the linked dupe. So how do we count this then? No feedback means dupe didn't help? Or did help?

Actually, it doesn't matter. Because if no negative feedback is the measure, then linking to References cannot be bad, because there is almost no negative feedback. If upvotes are the measure, then linking to a Reference is also not bad, because it has 389 upvotes and 271 favorites. And if positive feedback is the measure, then we have to consider the entire practise of closevoting as ineffective.

Let's talk about Form.

I have always been an advocate of the Digest Format for References for reasons outlined. When I was told about the new Reference in the PHP chat, I assumed it would be in that format. Digest is my favorite approach, because it is effectively a tag wiki on steroids:

1. It shows up in the FAQ and Suggestions, which gives it much more visibility.
2. It collect suitable dupes to close with
3. It helps OPs to find possible Q&A for their problem more easily
4. It helps contributors to find existing Q&A to turn into Canonicals
5. It doesn't take away from existing questions
6. It doesn't rely on quality content to be provided in the Reference

You could also think of it as a superdupe. When we close a question as a dupe, it will say: this is a dupe of X. The Operator Reference (since it has no answers, except for that one where there was no dupe for) is effectively like a closed question saying exactly that: "your question is a dupe of one of these. go find it in the list". In that regard, the Digest format isn't too far off from what we expect formally.

In case of the Operator Reference, I get no reputation from it (CW). I even was peer pressured to get it denormalized from me, so I cannot get any badges from it*.

^{* despite the day it took me to compile the initial list and the effort I put into maintaining it over the years and other, failed attempts at creating References gaining their creators badges for years. Note: after three years I've finally had it assigned back to me.}

Cause and Effect

I absolutely agree that this Reference format is not a real question. But that's not the point. It wasn't meant as a question in the first place. That the Operator Reference exists is merely an expression of StackOverflow's failing processes and tools. The current tag wikis are a failure. The required effort to cut down on dupes is too time consuming. And "loving the dupes" doesn't help the situation at all. It makes it worse.

Also, keep in mind that we are developers. If there is anything we really know how to do, than it is self-organizing ourselves and improving our tools. This is exactly what is happening here. It's pretty much Agile. We are adapting to the realities in the PHP tag.

TL;DR

References are not real questions, but it doesn't matter because they don't intend to be. The Operator Reference has undeniably proven it's worth to the PHP tag. The Error Reference could achieve the same if given the chance. If anything, we should discuss whether it's current form should be changed to a different format, e.g. the Digest format.

The continuous attempt at creating References are symptoms of failing tools on StackOverflow. We should look at the root causes and either accept the References as the best cure to these problems or come up with better ways to solve them. Discussion about better ways should take into account that the people in the PHP tag likely know best which challenges they face in there and how they can be solved.

Answer 4

The question is so useful that it's actually useless.

Now, when someone has that question, instead of closing it as a duplicate of the best answered version out there, we're supposed to close it as a duplicate of that monstrosity?

Can you imagine the user experience of a new user having to navigate that document just to figure out which question/answer meets their needs?

We know from experience that the Stack Exchange model doesn't work for what they're trying to do. It only works in the most general cases, like a list of programming books. Even then, of course, it gets unwieldy, fast.

This question should not exist. It does not add any usefulness to the people who actually get their questions closed as a duplicate of this question, and it subverts the Q & A nature of the site by completely negating the "Q" part.

I think the content should be moved to the tag wiki for that tag, if the PHP people are really hankering to keep it around.

Answer 5

Well, I'd much rather a single, so-called NARQ, than have thousands (I'm not exaggerating, thousands) of localized duplicates which serve no value to the site.

Ideally speaking, this is the job of the php Tag Wiki. There are technical problems with this approach.

• It's not space efficient.
• It doesn't appear in search.
• I can't close a question while referring to it.

Until those concerns are attended to, I think this is actually the best solution the current site allows.

Answer 6

There is way, way too much information to have a single post that attempts to explain (or even link to explanations of) all of the PHP errors. This question will only grow over time, making it both difficult to maintain (both to include new error messages, or new solutions or causes of existing error messages) as well as find information for those who actually need it. All of that information also makes it much, much harder for someone looking to solve their problem to find an answer. They need to sort through all of the other errors, and all of the unrelated causes of their error to get help.

If the goal is to stop people from asking duplicate questions, it likely won't help much. Those who don't do research before asking their question will ask it regardless of whether or not this question exists. Those who do take the time for quality research will most likely find a suitable answer if that answer is readily accessible. If they can't, then it's unlikely to be a poor quality question that this reference is designed to filer out; it's likely to be a more difficult problem.

Others have said that they just want a single question to close all of the "what does this error message mean?" questions as a duplicate of, rather than closing it as a duplicate of another question asking about that same error message. This is contrary to SO's principle that all questions be met with an answer, not to a link that contains another link that contains another link that might be an answer. Unless someone is asking what every PHP error means (in which case, it would be NARQ) it wouldn't be an exact duplicate. Even if this question does stick around, it shouldn't be used as the target for duplicates.

If this question does stick around though it's clear that it will be used as the target of duplicates (based on the fact that many PHP regulars have stated that intent in the comments here and in that question).

A question asking for an explanation of an error message should only be closed as a duplicate of another question asking about that same error message. If no such question exists (or you can't find one) the don't close it as a duplicate. If the unclosed duplicates don't have good answers then answer one of them. If that question/answer are sufficiently useful they will get upvotes and will start showing up in the possible duplicates when asking questions or voting to close as a duplicate (and in Google).

Answer 7

I don't think this is a good idea.

If a question is worth answering, it will be a good question on Stackoverflow. Therefore, all these errors can have their own questions and answers. If the question is posed right, it will not be closed as too localized.

As for having an index of errors, I believe tag wikis are made for just that purpose. In a tag wiki a list of these errors could exist for easy reference.

What this question will not do is stop the amount of duplicates as people will not be aware of this question when they pose their own. If there would be a good question and answer on the single error, it would pop up as "related question" and hence might prevent a new duplicate from being created.

Answer 8

I have to object to this question. While it does contain much useful information, what I see is a post trying to answer all questions where an error was referenced. Most of these errors contain enough information right there in the error message to understand (more or less) where to start your debugging.

The concept that one post could cover all PHP error messages and how to debugging them is slightly overzealous IMO.

A simple example would be -

Parse error: syntax error, unexpected T_XXX

Are we as Stack Overflow users supposed to tell users that there is a syntax error here? Or where it is exactly? Stack Overflow is not a code review or debugger service.

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I'd like to reference @bart's comment as well -

...What I do fear though is that a question like this will have a similar outcome of usage as "What Stack Overflow is Not" had...

One thing to worry about is the possibility that once people notice a question asking about a certain error message (contained in the CW post), the "accepted" behavior will be to simply leave a link as a comment to the post. We have to remember here that when dealing with these types of problems, more often than not we are dealing with new (possibly in-experienced) users. Linking to a massive post containing loads of text might actually be counter productive. These users failed to do the initial research of looking up the error messages in the documentation. Do we really expect them to read over a generic explanation of the error not related at all to their actual code causing the error?

Answer 9

I feel the current text at the beginning of the debugging reference does not explain well enough the most important problem it tries to address. The purpose of this reference never was to reference ALL the existing error messages!

Have a look at the new php questions:

• every day there is a new question about headers already sent
• every day there is a new question about mysql_fetch_array() expects parameter 1 to be resource, boolean given
• every day there is a new question about You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near...

and so on...

Almost all these new questions currently end up being closed with the reason Not constructive or Too localized. The problem is, this explanation doesn't help much the OP.
All these new questions should actually be closed as duplicates of existing questions, but the problems are:

• it is often very hard among the hundreds (or sometimes thousands) of existing duplicates to find a question where the accepted answer explains correctly what the problem is, and what to do
• the answers in existing questions are almost always providing a specific answer to the specific problem explained by the OP, and do not explain the problem globally

When closing such a question, it would be nice to close it as a duplicate, and be able to easily provide a link to an existing question with a very good answer addressing the problem the OP encountered.

This debugging reference is an attempt to:

• ease the work of the people who cast close-votes by providing a list of answers to refer to
• when applicable, close questions as duplicates and provide a link to the debugging reference (instead of closing as Not constructive or Too localized)

After reading the comments, I think the debugging reference should rather be a list of links (and only that) to other questions. Each question would address only one error or problem, and there would be only one answer to the question. All of that would be Community Wiki, as the current debugging reference is. If we do it this way, it would probably be better:

• each page contains only one question, so it can't be closed as "Not a real question"
• when voting to close a question, we can provide a link to the specific "reference question" that properly addresses the problem

Answer 10

I don't really have a problem with the "wiki"-ness of it. I don't even have a problem with it not being a tag wiki...no one looks at tag wikis. Not even Google. I don't consider a tag wiki a viable alternate spot for this. If this were a tag wiki no one would ever find it (except people shouting, exasperated, "Why didn't you look at this tag wiki no one looks at") and it would be useless for duplicate closures.

However, my problem boils down to this:

Surely there should be one question for each item on the list, and in most cases, there probably already is. – rjmunro

There probably are (many) questions for each of these. IMO, this canonical question would be better as a set of links to the specific, existing answers instead of attempting to replace those individual questions/answers.

It's still useful for the "but I want a dupe to close as" purpose then; if something's a dupe on the list, close it as a dupe of the list. If it's not, don't close but add that new question/answer to the list. IMO that makes a lot more sense, and it's already abusive enough of the question/answer concept. Perhaps it's still too far from a question, but I think it's a better solution than this.

Answer 11

I'm new to the community and don't understand all the ins and outs of how it works. I'm not sure whether my opinion holds as much value as a veteran's, but I probably at least bring fresh eyes. I personally feel that sometimes the veterans forget what it was like to be a new user.

What I really like about the PHP Errors Reference:

• All the answers have the same format.
• There is one clear answer for each error.
• As a CW, one answer gets improved upon instead of having multiple partial answers.
• The errors are easy to find; the links at the top use the exact error text.
• There is very little clutter.

The problems I see with the the dupes:

• The question and answers are too localized.
• Because they are easy to answer,
  • there is an abundance of mediocre answers.
  • there is a lot of clutter.
• If there are any good answers, they aren't accepted and don't float to the top.
• The 'Possible Duplicate' links often send one around in circles.

Community Objections:
Upon reading through the answers and comments on this page, it seems there are a few recurring objections.

• There are a large number of possible error messages and this page could grow so large as to be unusable. Counter Argument: While there are a lot of error messages, there are a limited number of common error messages that come up over and over and over again.

• What happens if every language wants to have their own error reference like this? Counter Argument: I believe¹ PHP is one of the most popular programming languages on the Internet especially among newbie programmers which, I think, has a direct effect on the volume of users asking questions about common error messages.

• The dupes should be closed against an existing question. Counter Argument: I don't think this works well for the reasons I've already mentioned.

  Plus, I would much prefer to be directed to a reference rather than having to wade through the clutter of mediocre answers (and the attached comments, by experienced users, stating why one should not follow the advice in the answer). If you aren't going to answer the question directly, then give me a reference I can use. Don't make me try to figure out how someone else's question applies to my circumstances.

  Would I let you know if the other question failed to help? Probably not. I'd probably just visit the next link in Google.

• Do you really expect this will stop users from posting dupes? Counter Argument: I'm not sure whether it will help in that regard or not. I think it will help some if made visible enough. But, I'm more interested in having a quality link to provide users with or close dupes against. The experienced users have to do more than just manage the dupes; they have to warn users against implementing the bad answers. If there was one question (or a short list of questions) that was considered the quality question to close against, I think this would make it easier to consistently, and quickly, close the dupes. Right now, many never get closed and the ones that do get closed are closed against different questions. If you follow the 'Possible Duplicate' links you often end up going in circles.

• The format, with each answer only answering part of the question, is not how SO was designed to be used. Counter Argument: So what's the solution then? Do we create individual questions and answers?

  The problems I see with creating new individual questions and answers:

  • My understanding is that you can't use a title that already exists. So how do we give them effective titles?
  • What's to stop these from being closed as dupes?
  • What's to stop these from accumulating clutter and mediocre answers?

Tag Wikis:
I only learned about these today because of this post. Perhaps they should at least be explained in the FAQ. This does seem like the ideal place to put this type of information if it could be overhauled to serve the needs of the community as others have already aptly described. Has this been submitted as a feature request?

In Conclusion:
I realize that SO is designed as a Q&A site, but the goal is to be useful to its users. I think the main thing we should be asking ourselves is how to best reconcile these two purposes.

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^{1: This is only my general impression. If someone has stats to support or disprove this theory, I'd appreciate it.}