# Undefined reference error

**URL:** <https://www.ruby-forum.com/t/undefined-reference-error/231164>\
**Category:** GNU Radio\
**Created:** [July 24, 2014, 3:34pm UTC](https://www.ruby-forum.com/t/undefined-reference-error/231164 "2014-07-24T15:34:16Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [July 24, 2014, 3:34pm UTC](https://www.ruby-forum.com/t/undefined-reference-error/231164/1 "2014-07-24T15:34:16Z")

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Hi there,

I’m run into a linker error when I build my OOT module; Hereafter what I  
get  
when typing sudo make:  
\*  
libgnuradio-ssg.so: undefined reference to «  
gr::filter::firdes::window(gr::filter::firdes::win\_type, int, double) »\*  
For information, I use gnuradio 3.7.3 on fedora 20 and the version 4.8.2  
of  
gcc.

I know it could be handled by modifying cmake files, but I don’t know  
which  
one and how !  
Could you please help me fix this.

Greetings,  
Mohamed

–  
View this message in context:  
[http://gnuradio.4.n7.nabble.com/Undefined-reference-error-tp49559.html](http://gnuradio.4.n7.nabble.com/Undefined-reference-error-tp49559.html)  
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---

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**Author:** ![mohamedx](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/b77776/32.png) [@mohamedx](https://www.ruby-forum.com/u/mohamedx)\
**Post date:** [July 24, 2014, 3:43pm UTC](https://www.ruby-forum.com/t/undefined-reference-error/231164/2 "2014-07-24T15:43:43Z")

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Hi Mohammed,

first: never “sudo make”. whereever that came from; running a build  
process as root is generally a bad idea.

John M. asked nearly exactly the same question (with gr-fft instead  
of gr-filter) 17 hours ago, so please refer to that thread for a  
(potential) solution.

Greetings,  
Marcus

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**Author:** ![mohamedx](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/b77776/32.png) [@mohamedx](https://www.ruby-forum.com/u/mohamedx)\
**Post date:** [July 24, 2014, 4:00pm UTC](https://www.ruby-forum.com/t/undefined-reference-error/231164/3 "2014-07-24T16:00:22Z")

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Also,

did you read the manual page for this?

[http://gnuradio.org/doc/doxygen/index.html#oot\_config\_page](http://gnuradio.org/doc/doxygen/index.html#oot_config_page)

M

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**Author:** ![mohamedx](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/b77776/32.png) [@mohamedx](https://www.ruby-forum.com/u/mohamedx)\
**Post date:** [July 24, 2014, 4:40pm UTC](https://www.ruby-forum.com/t/undefined-reference-error/231164/4 "2014-07-24T16:40:09Z")

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Hi Marcus,

Thanks for helping me to fix this, it’s working well.  
Here is the direct link to the disussion you’ve mentionned:  
[http://gnuradio.4.n7.nabble.com/Out-of-Tree-linker-error-libgnuradio-MYMOD-so-undefined-reference-to-gr-fft-fft-complex-execute-td49549.html](http://gnuradio.4.n7.nabble.com/Out-of-Tree-linker-error-libgnuradio-MYMOD-so-undefined-reference-to-gr-fft-fft-complex-execute-td49549.html)

In other hand, when I add another implementation class into the lib  
directory - it doesn’t have an abstract class in include directory, the  
make  
process returns the same error, but this time it concerns the  
constructor of  
this new imlementation class I just added !  
I’ve mentioned the .cc file in CMakeLists.txt existing in lib directory,  
but  
I still get the same error.

Any ideas that can help me with this new issue ?

Greetings,  
Mohamed

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Sent from the GnuRadio mailing list archive at [Nabble.com](http://Nabble.com).