AW: Import Error "undefined symbol"

Hi, thank you very much. Your hints helped me towards the right direction.

I added:

"find_package(Gnuradio "3.10" REQUIRED fft blocks analog filter digital) " to the CMakeLists.txt in gr-mymodule

and i added

"target_link_libraries(gnuradio-mymodule gnuradio::gnuradio-runtime gnuradio::gnuradio-fft gnuradio::gnuradio-blocks gnuradio::gnuradio-analog gnuradio::gnuradio-filter gnuradio::gnuradio-digital)"

If I now do "import mymodule" in a python terminal, it works now, but... I am not able to open gnuradio anymore:

<<< Welcome to GNU Radio Companion 3.10.5.0 >>>

Block paths:

/home/niklas/.grc_gnuradio

/usr/share/gnuradio/grc/blocks

/usr/local/share/gnuradio/grc/blocks

Loading: "/home/niklas/Workspace/Niklas_flowgraphs/Transceiver_Station_1.grc"

Segmentation fault (core dumped)

Would be great, if anyone has an idea

Best,

It might be as simple as adding "gnuradio::gnuradio-digital" to the "target_link_libraries" in your mymodule/lib/CMakeList.txt.

Maybe you also have to adjust the "find_package" in your mymodule/CMakeList.txt to something like "

find_package(Gnuradio
"3.10" REQUIRED COMPONENTS digital)

From: Brandon Smith [mailto:blsmit5728@gmail.com]

Sent: Monday, March 20, 2023 at 11:37 UTC+1

Subject: Import Error "undefined symbol"

You may have not linked a library in your cmake. Looks like you wanted digital packet header but have not provided a library for it. Perform ldd on /usr/local/lib/x86_64-linux-gnu/libgnuradio-mymodule.so.1.0.0 and see if the missing library is shown.

On Mon, Mar 20, 2023 at 4:59 AM Beckmann, Niklas <niklas.beckmann1@rwth-aachen.de> wrote:

Hi everybody,

in a Flowchart, I am using an Import Block.

Gnuradio shows me the following:

Param - Import(imports):

Import "import mymodule" failed.

The module "mymodule" is installed properly and without any error. The blocks of this module are working (except of the one that i need the import for) and showed on the sidebar where all the blocks are found.

To get more information about the error, I opened a pyhton termial with the following result:

niklas@niklas:~$ python

Python 3.8.10 (default, Nov 14 2022, 12:59:47)

[GCC 9.4.0] on linux

Type "help", "copyright", "credits" or "license" for more information.

>>> import mymodule

Traceback (most recent call last):

File "<stdin>", line 1, in <module>

File "/usr/local/lib/python3.8/dist-packages/gnuradio/mymodule/__init__.py", line 18, in <module>

from .mymodule_python import *

ImportError: /usr/local/lib/x86_64-linux-gnu/libgnuradio-mymodule.so.1.0.0: undefined symbol: _ZTIN2gr7digital21packet_header_defaultE

I wasnt able to solve this problem now for a few days already, and therefore, I was wondering, if anyone has an idea, how to solve that, since also google did not really help. If I need to provide any further information, I will of course do so (I just did not know, what else could be important for this).

Thank you very much for your help. 😊

Kind regards,

--

Sent from Gmail Mobile

From:	Beckmann, Niklas
Subject:	AW: Import Error "undefined symbol"
Date:	Mon, 20 Mar 2023 17:19:00 +0000