# Problem with 3.6.2

**URL:** <https://www.ruby-forum.com/t/problem-with-3-6-2/223683>\
**Category:** GNU Radio\
**Created:** [October 13, 2012, 8:37pm UTC](https://www.ruby-forum.com/t/problem-with-3-6-2/223683 "2012-10-13T20:37:03Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![aris](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/258eb7/32.png) [@aris](https://www.ruby-forum.com/u/aris)\
**Post date:** [October 13, 2012, 8:37pm UTC](https://www.ruby-forum.com/t/problem-with-3-6-2/223683/1 "2012-10-13T20:37:03Z")

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Hi,

I was using 3.6 with no issues. Today I updated to 3.6.3 and get the  
following error when I try to start the flowgraph. I did rebuild all  
parts of my application.

terminate called after throwing an instance of ‘Using Volk machine:  
sse4\_1\_64\_orc  
std::invalid\_argument’  
what(): gr\_buffer\_add\_reader: nzero\_preload must be \>= 0  
The program has unexpectedly finished.

Does anyone have any idea where I could start looking?

thanks,  
steve

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**Author:** ![stephen](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/96bed5/32.png) [@stephen](https://www.ruby-forum.com/u/stephen)\
**Post date:** [October 14, 2012, 7:07pm UTC](https://www.ruby-forum.com/t/problem-with-3-6-2/223683/2 "2012-10-14T19:07:30Z")

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On 10/13/2012 11:36 AM, Stephen wrote:

> what(): gr\_buffer\_add\_reader: nzero\_preload must be \>= 0  
> The program has unexpectedly finished.
> 
> Does anyone have any idea where I could start looking?

set\_history needs to be at least 1.

(because this actually means a history of user\_history\_setting-1 is  
prepended to the start of the buffer)

-josh

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**Author:** ![stephen](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/96bed5/32.png) [@stephen](https://www.ruby-forum.com/u/stephen)\
**Post date:** [October 15, 2012, 12:03am UTC](https://www.ruby-forum.com/t/problem-with-3-6-2/223683/3 "2012-10-15T00:03:10Z")

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On 10/14/2012 12:06 PM, Josh B. wrote:

> set\_history needs to be at least 1.
> 
> (because this actually means a history of user\_history\_setting-1 is  
> prepended to the start of the buffer)
> 
> -josh

thanks for the reply but I don’t know what that means. What is  
set\_history? I don’t explicitly use gr\_buffer in my application. I do  
use gr message queues. But all of my message queues are initialized  
with a size.

steve

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**Author:** ![stephen](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/96bed5/32.png) [@stephen](https://www.ruby-forum.com/u/stephen)\
**Post date:** [October 15, 2012, 6:28pm UTC](https://www.ruby-forum.com/t/problem-with-3-6-2/223683/4 "2012-10-15T18:28:40Z")

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On 10/14/2012 03:02 PM, Stephen wrote:

> > -josh
> 
> thanks for the reply but I don’t know what that means. What is  
> set\_history? I don’t explicitly use gr\_buffer in my application. I do  
> use gr message queues. But all of my message queues are initialized  
> with a size.

Somewhere (probably) there is a block in your flow graph that is calling  
set\_history(0). Perhaps you have some filter taps that are unset (empty  
array)?

-josh