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Comment by alyandon | Hacker News Reader

I myself ran across this same scenario many years ago with a similar amount of hair pulling and eventually concluding that the GNU libstdc++ allocator wasn't reusing memory properly. Unfortunately, I was never able to pare down the application to the point that I had a reproducible test case to report upstream.

GLIBCPP_FORCE_NEW was the solution for the near term and since I was deploying on Solaris boxes I eventually switched to the Sun Forte C++ compiler.

It really bugs me that this problem still exists. :-/

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It really bugs me that nobody links bug on bugtracker or filed it. I know I'm asking a lot and being an ass.

I searched GCC Bugzilla and found one result[0] for GLIBCPP_FORCE_NEW.

[0] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=13823

Edited to add the following text.

There is one result[1] for GLIBCXX_FORCE_NEW.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65018

I think these days it goes by GLIBCXX_FORCE_NEW

Default bugzilla search doesn't include resolved, verified, and closed bugs. That said, I only found one slightly relevant, which was resolved invalid, saying the env var should be used: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10183

And that's just due to not freeing the pools, not whatever is the complex problem here.

Yeah: people run into issues and somehow feel "obviously everyone else ran into this same issue and it was never fixed so they must not want to fix it" without it ever really occurring to them that maybe almost no no one runs into this problem and no one knows it exists, or even that it could be their code that is broken. We all know "I compiled my code with -O0 and it started working" is almost never due to "there is a bug in the code optimizer", and this one sounds extremely similar. If people think they have found a bug, and they want to feel righteous and haughty over how it never got fixed, they really need to be demonstrating it is actually a known bug (and maybe you were being sarcastic, but I will just state flatly: being bothered when people do not does not make you the ass).

No, that's a reasonable expectation. Unfortunately, developers often don't appreciate bug reports and become defensive. File a bug report and you will be expected to provide a reproducible test case, or your bug will get closed. This isn't always possible, and the reporter might not be able to dedicate the time to do this.

I used to file lots of bug reports, because I know that as a developer, I'd want them. Every bug report is valuable, even if it's not reproducible. It happened to someone, so it surely also happened to 10 other people who did not report it, it's important.

Unfortunately, bug reports often get responses like "cannot reproduce", "please provide more details which is oh, about a day or two of work". Well, not everyone has a day or two to spend on a bug report, especially if you (like me) hit software bugs regularly.

These days I very rarely file bug reports. It just isn't worth the effort, as most developers do not appreciate the bug report. The dominating perception is that bug reports are annoyances that need to be closed ASAP, and if it isn't easily reproducible, it doesn't exist.

So I'm not surprised that nobody opens bugreports for bugs like the one described by the OP. Not easily reproducible? Rarely occurs? It's highly probable that nobody would care.

BTW, I ask users of my software to please do report bugs. Every bug report is a valuable data point, even if it isn't reproducible. And I do appreciate the effort that it takes just to file a bug report.

The problem with libstdc++ is that, in my experience, 90% of bug reports are user error. That means non reproducible bug reports have almost no value.

I know you were probably just throwing out the “90%” statistic, but if you take that as a given, the implication that 10% of the libstdc++ bugs on file are legit is a worrisome notion in and of its own right. I don’t want to be responsible for triaging those bugs (and nor do you, I am guessing; this being why the reports are valueless) but the fact that this is the bug rate in this, a gold-standard library in common, ubiquitous use… well as far as I can see, this is the context in which that the OP’s article should be considered.

… I build all of my C++ projects with Clang and link them against libc++, so I don’t know if I am dodging a very high-caliber bullet (so to speak) or if the other shoe will drop at some point, and I will find myself going down the OP’s rabbit-hole of library-bug investigation.

You are right, it's probably a lot less than that.

The bug quality is higher than you might expect, because you have to register with bugzilla, and most bug reports are with development versions, as bugs are shaken out of new features. There are very few bugs in released versions, and where those bugs exist they are often of the form "stupid type where I have redefined & doesn't compile, while the standard technically days it should", where most users would never got them. Wrong answer or crash bugs in releases are extremely rare, although they could be rarer -- the test suite has less coverage than I would personally like.

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