Unhandled... floating point exception.

[yure16]

Running Ubuntu 12.10. So, everytime I export a song, either to .wav or .ogg, the program freezes the whole system. Word from the Terminal says it was a floating point exception. Also, when I click the file in presets > audiofileprocessor > orion.xpf, so I can load the preview, I get segmentation faults. So, anyways... the orion thing isn't my main concern as it's a preset and I can make it with orion_string01.ogg. What really worries me is the freezing upon exporting.
Gnu Debugger told me:

Qt has caught an exception thrown from an event handler. Throwing
exceptions from an event handler is not supported in Qt. You must
reimplement QApplication::notify() and catch all exceptions there.

Qt has caught an exception thrown from an event handler. Throwing
exceptions from an event handler is not supported in Qt. You must
reimplement QApplication::notify() and catch all exceptions there.

terminate called after throwing an instance of 'std::bad_alloc'
what(): std::bad_alloc

Program received signal SIGABRT, Aborted.
0xb7fdd424 in __kernel_vsyscall ()

Now, backtracing...

#0 0xb7fdd424 in __kernel_vsyscall ()
#1 0xb69311df in raise () from /lib/i386-linux-gnu/libc.so.6
#2 0xb6934825 in abort () from /lib/i386-linux-gnu/libc.so.6
#3 0xb6afa8ad in __gnu_cxx::__verbose_terminate_handler() ()
from /usr/lib/i386-linux-gnu/libstdc++.so.6
#4 0xb6af84f3 in ?? () from /usr/lib/i386-linux-gnu/libstdc++.so.6
#5 0xb6af852f in std::terminate() ()
from /usr/lib/i386-linux-gnu/libstdc++.so.6
#6 0xb6af8825 in __cxa_rethrow () from /usr/lib/i386-linux-gnu/libstdc++.so.6
#7 0xb732c7e7 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /usr/lib/i386-linux-gnu/libQtCore.so.4
#8 0xb7331cba in QCoreApplication::exec() ()
from /usr/lib/i386-linux-gnu/libQtCore.so.4
#9 0x080ae99f in main ()

I'm no programmer, so I'm stuck.x3

[brandystarbrite]

I'm not a programmer. And I don't use Ubuntu. I wonder if saving it as "16 bit integer" would solve your problem?
There's a "depth" option, when you try to export your files. Try changing it to 16 bit integer. And pray that helps.
I hope your computer doesn't freeze again.
If not, stick around on the forums and someone will come to your aid.

[yure16]

I'm not a programmer. And I don't use Ubuntu. I wonder if saving it as "16 bit integer" would solve your problem?
There's a "depth" option, when you try to export your files. Try changing it to 16 bit integer. And pray that helps.
I hope your computer doesn't freeze again.
If not, stick around on the forums and someone will come to your aid.

I will most likely wait for an answer.-w- And no, I always use 16-bit Integer, since I prefer it's sound over 32-bit float. I disabled the loop in the song even, thinking it was an issue with that "magnetic loop point" thing.x3 Looking back at it, I find it silly.
If the strong or the able is reading this reply, it all started after the most recent update of LMMS that I received from the ppa: dns/sound. It was two days ago.

[orpheon7]

Tobias Doerffel via lists.sourceforge.net

11:52 PM (18 hours ago)

to me, lmms-devel
Hi,

2012/11/13 Orpheon <my_email@gmail.com>:
> https://sourceforge.net/apps/phpbb/lmms ... 89&start=0

Which Qt version is this? Just asking because it looks like a Qt bug -
from what I can see from the backtrace. Is anyone able to reproduce
the issue? Maybe the guy can post the MMP file somewhere?

Toby

[yure16]

Tobias Doerffel via lists.sourceforge.net

11:52 PM (18 hours ago)

to me, lmms-devel
Hi,

2012/11/13 Orpheon <my_email@gmail.com>:
> https://sourceforge.net/apps/phpbb/lmms ... 89&start=0

Which Qt version is this? Just asking because it looks like a Qt bug -
from what I can see from the backtrace. Is anyone able to reproduce
the issue? Maybe the guy can post the MMP file somewhere?

Toby

Wowsers, Tobydox wants to hear from me!
Tell him that it doesn't need to be a specific file or specific configuration; the program will freeze the system up whenever I export, no matter if it's a short song with a few instruments or a huge song with several instrument files. If it's a Qt bug, should I upgrade my version of it (or downgrade)? Also, the orion.xpf problem was fixed by the most recent package I received from the PPA, but exporting is still a hassle.
Dunno what is my version of Qt.

[yure16]

https://rohieb.wordpress.com/2010/07/08 ... and-slots/

According to this post, the newer versions of Qt doesn't handle exceptions by default and, thinking about that, maybe my version of Qt was upgraded recently. I would have to

Overwrite the function bool QApplication::notify(QObject * receiver, QEvent * event) so that it catches all thrown exceptions.

, but I suppose I have to do it in main.cpp in the sourcecode and then recompile. Fact is, everytime I try to compile from source, I fail.-w- Downgrading Qt doesn't seem easy, not even easier than altering a file in the source (supposing that it's what I should do). I read somewhere else that this is a problem affecting qt-4.8.1-3 and that I'm supposed to downgrade to qt-4.8.1-1, but no one explains the method to do that.

[yure16]

As I suspected, this is a problem with the most recent version of LMMS found in the PPA. I used ppa-purge to downgrade to 0.4.10 and the problem disappeared, exporting is working fine now. The version in the PPA is lmms 0.4.13-stable.git.2254-1.1~12.10 and I received two atualizations of it in a time spam of one week or so. Is there something going on there? If it's a problem in the packages I'm receiving from the PPA, I will just wait for the next release, because I have been liking some features in 0.4.13 and I would like to keep it. Fact is, I found where the problem is, but isn't up to me to fix, it seems.

[yure16]

My friend, Amenophis, told me:

If you've never compiled a program, you're in for a lot of headdache.

Your app did a bad memory allocation, which threw the exception. The question is why the allocation failed. You'll need to figure out how much memory it tried to allocate and why it failed. A simple error could be you pass it a negative value, which looks like a huge number. That could happen if the math is screwed up.

So you have 2 bugs: that one, and the fact the exception is not properly handled...

[orpheon7]

Hi,

2012/11/20 Chrissy McManus <chrissy.mc.1@hotmail.co.uk>:
> Yes i can reproduce this same crash on ubuntu and the very latest git pull
> as
> from a few days ago, lmms was working fine until a few days ago, so i
> believe
> that it is a very recent commit causing this issue and not Qt as i checked
> my
> package install/update history and i havnt had a qt update for some time.

Is there a possibility you can track down this regression via
git-bisect? Or at least give a behaviour how to reproduce the problem?

Best regards

Toby

Also sent the link again.

My friend, Amenophis, told me:

If you've never compiled a program, you're in for a lot of headdache.

Your app did a bad memory allocation, which threw the exception. The question is why the allocation failed. You'll need to figure out how much memory it tried to allocate and why it failed. A simple error could be you pass it a negative value, which looks like a huge number. That could happen if the math is screwed up.

So you have 2 bugs: that one, and the fact the exception is not properly handled...

Your friend is right, the problem is that it's an incredibly general error and could generally be caused by a whole lot of things.
So finding it still requires narrowing down the exact version of the buggy program and what you did to try to find what requested bad memory.

The bug not being checked though is a true point.

[yure16]

Hi,

2012/11/20 Chrissy McManus <chrissy.mc.1@hotmail.co.uk>:
> Yes i can reproduce this same crash on ubuntu and the very latest git pull
> as
> from a few days ago, lmms was working fine until a few days ago, so i
> believe
> that it is a very recent commit causing this issue and not Qt as i checked
> my
> package install/update history and i havnt had a qt update for some time.

Is there a possibility you can track down this regression via
git-bisect? Or at least give a behaviour how to reproduce the problem?

Best regards

Toby

Also sent the link again.

My friend, Amenophis, told me:

If you've never compiled a program, you're in for a lot of headdache.

Your app did a bad memory allocation, which threw the exception. The question is why the allocation failed. You'll need to figure out how much memory it tried to allocate and why it failed. A simple error could be you pass it a negative value, which looks like a huge number. That could happen if the math is screwed up.

So you have 2 bugs: that one, and the fact the exception is not properly handled...

Your friend is right, the problem is that it's an incredibly general error and could generally be caused by a whole lot of things.
So finding it still requires narrowing down the exact version of the buggy program and what you did to try to find what requested bad memory.

The bug not being checked though is a true point.

I have idea of how to do that. I just learned the gdb trick because I'm working as composer for a game and my boss, who is programmer, told me about said tool to track bugs. If someone is willing to teach me how track down the regression, I'll gladly do it.