Trouble with OOT modules on Windows with Conda

[Florian Euchner]

Hello everyone,

I am having trouble compiling OOT modules on Windows (Windows 10, Visual Studio 
2017 14.16.27023).
As far as I can tell, my problems affect any OOT module, so I will just use 
gr-correctiq [1] as an example.

I am inside a Conda environment as detailed in the CondaInstall guide [2] and 
my GNURadio has been built from the sources following the instructions in [3].
I can compile and install OOT modules just fine, but after installation, they 
fail to import with the following error:

# python
> > > import correctiq
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\florian\.conda\envs\grdev\lib\site-packages\correctiq\__init__.py", 
line 18, in <module>
    from .correctiq_python import *
ImportError: generic_type: type "correctiq" referenced unknown base type 
"gr::sync_block"

The same error occurs when executing a flowgraph with any block from the 
correctiq module inside GNURadio companion.

I have seen a similar question on the mailing list recently [4], where the 
issue turned out to be different pybind versions.
However, this can't be the case for me, since I have compiled GNURadio from 
source inside the same Conda environment (GNURadio version is latest master as 
of today, but also occurs for 3.9.5 and 3.10).
Also, my problem appears to specifically occur on Windows and not on Linux.

Any idea on how to solve or debug it? Any help is greatly appreciated!

Kind regards,
Florian

[1]: https://github.com/ghostop14/gr-correctiq
[2]: https://wiki.gnuradio.org/index.php?title=CondaInstall
[3]: 
https://wiki.gnuradio.org/index.php?title=CondaInstall#Building_GNU_Radio_from_source_within_a_conda_environment
[4]: https://lists.gnu.org/archive/html/discuss-gnuradio/2021-05/msg00056.html