Problem building GNURadio / osmo*

[dongfang]

Hi all,

I am trying to get my old bladeRF X40 going again, and trying to follow this: https://github.com/Nuand/bladeRF/wiki/G ... d%3A-Linux . I have Ubuntu 24.04.LTS, gcc (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0 .

At this step: pybombs prefix init ~/pybombs/bladeRF -a bladeRF -R gnuradio-default

I get a lot of:
/home/x/pybombs/bladeRF/include/volk/volk_common.h:182:23: error: exponent has no digits
182 | const float a1 = +0x1.ffffeap-1f;
| ^~~~~~~~~~~
/home/x/pybombs/bladeRF/include/volk/volk_common.h:183:23: error: exponent has no digits
183 | const float a3 = -0x1.55437p-2f;
| ^~~~~~~~~~
/home/x/pybombs/bladeRF/include/volk/volk_common.h:184:23: error: exponent has no digits
184 | const float a5 = +0x1.972be6p-3f;
| ^~~~~~~~~~~

I tried to find solutions the lazy way, but this seems not to be a FAQ. It seems GCC doesn't get the hexadecimal decimal literals in there, and it should be passed (?) a something to enable C++17. I don't know how to do that from within the pybombs stuff, can I use an environment variable?

Does somebody know how I can get past this problem?

Thanks a lot -

Kind regards, Soren

[fnfunkin]

I ran into something very similar when building older GNU Radio stacks with newer GCC. In my case it turned out not to be a C++17 issue, but a mismatch in compiler flags—those hex float literals are valid, but only if the file is being treated as C99/C++11+ correctly. I fixed it by forcing PyBOMBS to use -std=gnu11 (for C parts) via CFLAGS/CXXFLAGS before running pybombs, or by patching the build config to explicitly set the standard.

If you’re new to this, it might help to check which files are being compiled as C vs C++—this error often pops up when a C file gets compiled with the wrong standard or flags.