# Howto Problems

**URL:** <https://www.ruby-forum.com/t/howto-problems/224630>\
**Category:** GNU Radio\
**Created:** [November 19, 2012, 9:09pm UTC](https://www.ruby-forum.com/t/howto-problems/224630 "2012-11-19T21:09:46Z")\
**Posts on this page:** 3\
**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:** [November 19, 2012, 9:09pm UTC](https://www.ruby-forum.com/t/howto-problems/224630/1 "2012-11-19T21:09:46Z")

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Trying to get howto-write-a-block to work. ‘ctest -V’ gives errors like:  
“…/gr-howto-write-a-block-3.6.0/lib/qa\_howto\_square\_ff\_test.sh: 8:  
qa\_howto\_square\_ff: not found” and the same for square2\_ff.

File “/home/tim/SDR/gr-howto-write-a-block-3.6.0/python/qa\_howto.py”,  
line  
24, in   
3: import howto\_swig  
3: ImportError: No module named howto\_swig

I’ve checked the directory and the qa files do exist. Do they need  
extensions added to them? howto\_swig.i also includes the correct files,  
but  
can’t be imported?

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**Author:** ![Brooke\_H](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/77aa72/32.png) [@Brooke\_H](https://www.ruby-forum.com/u/Brooke_H)\
**Post date:** [November 20, 2012, 8:03am UTC](https://www.ruby-forum.com/t/howto-problems/224630/2 "2012-11-20T08:03:40Z")

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Hi Brooke,

are you mixing hand-edited code and files generated by gr\_modtool?  
Also, can you manually import howto\_swig from the build/swig dir?

Besides, if you’re getting started, 3.6.0 is not the newest version of  
GNU Radio.

MB

On Mon, Nov 19, 2012 at 03:08:50PM -0500, Brooke H. wrote:

> 3: ImportError: No module named howto\_swig
> 
> I’ve checked the directory and the qa files do exist. Do they need extensions  
> added to them? howto\_swig.i also includes the correct files, but can’t be  
> imported?

> * * *
> 
> Discuss-gnuradio mailing list  
> [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
> [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio)

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<div class="post-metadata">

**Author:** ![Brooke\_H](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/77aa72/32.png) [@Brooke\_H](https://www.ruby-forum.com/u/Brooke_H)\
**Post date:** [July 9, 2013, 5:26am UTC](https://www.ruby-forum.com/t/howto-problems/224630/3 "2013-07-09T05:26:30Z")

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Hi  
I have the same problem  
I can manually import howto\_swig from the build/swig dir.  
but with build/python dir, it always show  
hi@OptiPlex-360:/home/sdr-optiplex/dev/gnuradio/gnuradio/gr-howto-write-a-block/build/python$  
python qa\_square\_ff.py  
Traceback (most recent call last):  
File “qa\_square\_ff.py”, line 4, in   
import howto\_swig as howto  
ImportError: No module named howto\_swig