Codec2 isn't detected properly (at least on NixOS)

[doronbehar]

On NixOS (linked issue: NixOS/nixpkgs#82263 (comment) ) we are having problems with how GR (3.8 and 3.9) detects Codec2.

With both GR3.8 and GR3.9, cmake seems to not find codec2 by it's own:

Configuring gr-vocoder support...
  Dependency Boost_FOUND = TRUE
  Dependency ENABLE_GNURADIO_RUNTIME = ON
  Dependency ENABLE_GR_FFT = ON
  Dependency ENABLE_GR_BLOCKS = ON
  Dependency ENABLE_GR_FILTER = ON
  Dependency ENABLE_GR_ANALOG = ON
  Enabling gr-vocoder support.
  Override with -DENABLE_GR_VOCODER=ON/OFF
Could NOT find Codec2 (missing: LIBCODEC2_INCLUDE_DIRS)
Could NOT find GSM (missing: LIBGSM_INCLUDE_DIRS)

Where codec2 has the following files in it's installation directory:

/nix/store/...-codec2/
├── bin
│   ├── c2dec
│   ├── c2enc
│   ├── drs232
│   ├── drs232_ldpc
│   ├── fdmdv_demod
│   ├── fdmdv_get_test_bits
│   ├── fdmdv_mod
│   ├── fdmdv_put_test_bits
│   ├── fm_demod
│   ├── fsk_mod
│   └── insert_errors
├── include
│   └── codec2
│       ├── codec2_cohpsk.h
│       ├── codec2_fdmdv.h
│       ├── codec2_fifo.h
│       ├── codec2_fm.h
│       ├── codec2.h
│       ├── codec2_ofdm.h
│       ├── comp.h
│       ├── comp_prim.h
│       ├── filter.h
│       ├── freedv_api.h
│       ├── freedv_api_internal.h
│       ├── fsk.h
│       ├── golay23.h
│       ├── horus_api.h
│       ├── kiss_fft.h
│       ├── modem_stats.h
│       ├── varicode.h
│       └── version.h
└── lib
    ├── cmake
    │   └── codec2
    │       ├── codec2-config.cmake
    │       └── codec2-config-release.cmake
    ├── libcodec2.so -> libcodec2.so.0.9
    ├── libcodec2.so.0.9
    └── pkgconfig
        └── codec2.pc

7 directories, 34 files

I.e it has the freedv api files, and indeed with 3.8 if I specify some Cmake files:

      "-DLIBCODEC2_LIBRARIES=${codec2}/lib/libcodec2.so"
      "-DLIBCODEC2_INCLUDE_DIRS=${codec2}/include"
      "-DLIBCODEC2_HAS_FREEDV_API=ON"
      "-DLIBGSM_LIBRARIES=${gsm}/lib/libgsm.so"
      "-DLIBGSM_INCLUDE_DIRS=${gsm}/include/gsm"

I don't see the lines:

Could NOT find Codec2 (missing: LIBCODEC2_INCLUDE_DIRS)
Could NOT find GSM (missing: LIBGSM_INCLUDE_DIRS)

And GR 3.8 builds fine and reverse dependencies of GR 3.8 that need these features are compiled correctly and work fine - qradiolink for instance (see: qradiolink/qradiolink#67 ).

But, now with GR 3.9 Specifying or not specifying the cmake flags results in the same behavior, but in either case cmake fails after configuring everything else and it's errors are:

gnuradio> CMake Error at /nix/store/5d7dgha0nl6hixhszb9x5pfczpblch1a-python3.8-pybind11-2.6.1/share/cmake/pybind11/pybind11Tools.cmake:151 (add_library):
gnuradio>   Target "vocoder_python" links to target "CODEC2::CODEC2" but the target was
gnuradio>   not found.  Perhaps a find_package() call is missing for an IMPORTED
gnuradio>   target, or an ALIAS target is missing?
gnuradio> Call Stack (most recent call first):
gnuradio>   cmake/Modules/GrPybind.cmake:120 (pybind11_add_module)
gnuradio>   gr-vocoder/python/vocoder/bindings/CMakeLists.txt:44 (GR_PYBIND_MAKE_CHECK_HASH)
gnuradio> CMake Error at /nix/store/5d7dgha0nl6hixhszb9x5pfczpblch1a-python3.8-pybind11-2.6.1/share/cmake/pybind11/pybind11Tools.cmake:151 (add_library):
gnuradio>   Target "vocoder_python" links to target "GSM::GSM" but the target was not
gnuradio>   found.  Perhaps a find_package() call is missing for an IMPORTED target, or
gnuradio>   an ALIAS target is missing?
gnuradio> Call Stack (most recent call first):
gnuradio>   cmake/Modules/GrPybind.cmake:120 (pybind11_add_module)
gnuradio>   gr-vocoder/python/vocoder/bindings/CMakeLists.txt:44 (GR_PYBIND_MAKE_CHECK_HASH)
gnuradio> CMake Error at gr-vocoder/lib/CMakeLists.txt:11 (add_library):
gnuradio>   Target "gnuradio-vocoder" links to target "CODEC2::CODEC2" but the target
gnuradio>   was not found.  Perhaps a find_package() call is missing for an IMPORTED
gnuradio>   target, or an ALIAS target is missing?
gnuradio> CMake Error at gr-vocoder/lib/CMakeLists.txt:11 (add_library):
gnuradio>   Target "gnuradio-vocoder" links to target "GSM::GSM" but the target was not
gnuradio>   found.  Perhaps a find_package() call is missing for an IMPORTED target, or
gnuradio>   an ALIAS target is missing?
gnuradio> -- Generating done

It seems like the something with the switch to pybind from swig broke something.

[ryanvolz]

Does https://github.com/gnuradio/gnuradio/pull/4476/files help with this? Because I suspect it might. That has also been backported to maint-3.9, although after the 3.9.1 release.

[doronbehar]

Does #4476 (files) help with this? Because I suspect it might. That has also been backported to maint-3.9, although after the 3.9.1 release.

Yes it does! But we still need to set for GR 3.9:

      "-DLIBGSM_FOUND=TRUE"
      "-DLIBGSM_LIBRARIES=${gsm}/lib/libgsm.so"
      "-DLIBGSM_INCLUDE_DIRS=${gsm}/include/gsm"

Otherwise:

gnuradio> CMake Error at /nix/store/yikabla1qm5n1gmgak9hzqy7sbagl6cq-python3.8-pybind11-2.6.1/share/cma
e/pybind11/pybind11Tools.cmake:151 (add_library):
gnuradio>   Target "vocoder_python" links to target "GSM::GSM" but the target was not
gnuradio>   found.  Perhaps a find_package() call is missing for an IMPORTED target, or
gnuradio>   an ALIAS target is missing?
gnuradio> Call Stack (most recent call first):
gnuradio>   cmake/Modules/GrPybind.cmake:120 (pybind11_add_module)
gnuradio>   gr-vocoder/python/vocoder/bindings/CMakeLists.txt:44 (GR_PYBIND_MAKE_CHECK_HASH)
gnuradio> CMake Error at gr-vocoder/lib/CMakeLists.txt:11 (add_library):
gnuradio>   Target "gnuradio-vocoder" links to target "GSM::GSM" but the target was not
gnuradio>   found.  Perhaps a find_package() call is missing for an IMPORTED target, or
gnuradio>   an ALIAS target is missing?
gnuradio> -- Generating done