Ho to use Limesdr and rtl dongles with GNURadio 3.8.2

[Christophe Seguinot]

    Hi
    
    I recently switched my computer to Ubuntu 20.04 and installed
    GNURadio 3.8.2.0 from ppa
    (http://ppa.launchpad.net/gnuradio/gnuradio-releases/ubuntu).
    Version 3.8.2 is the latest in this PPA and is installed by default.
    
    I also installed gr-osmosdr gr-limesdr and gr-rds using sudo apt
    install.
    
    Gnuradio is running fine in most cases. However, each time I run a
    flowgraph involving  SDR or LimeSDR Dongle I get the classical
    error:
    
        File "/home/-----/rds_rx.py", line 571, in __init__
            self.audio_sink_1 = audio.sink(audio_rate, '', True)
        AttributeError: 'int' object has no attribute 'sink'
    
    Looking into library folder /usr/lib/x86_64-linux-gnu I found that
    some 3.8.1.1 and 3.8.0 libraries are installed and probably
    conflicting with 3.8.2.0 libraries. For example, command ll
      libgnuradio-runtime* gives
    
        lrwxrwxrwx 1 root root      28 aug.  22 14:29
    libgnuradio-runtime.so -> libgnuradio-runtime.so.3.8.2
        lrwxrwxrwx 1 root root      30 juil. 31 15:23
    libgnuradio-runtime.so.3.8.1 -> libgnuradio-runtime.so.3.8.1.0
        -rw-r--r-- 1 root root 1077632 juil. 31 15:23
    libgnuradio-runtime.so.3.8.1.0
        lrwxrwxrwx 1 root root      30 aug.  22 14:29
    libgnuradio-runtime.so.3.8.2 -> libgnuradio-runtime.so.3.8.2.0
        -rw-r--r-- 1 root root 1077632 aug.  22 14:29
    libgnuradio-runtime.so.3.8.2.0
    
    It looks like 3.8.1 and 3.8.0 libraries have been installed when
    installing gr-osmosdr gr-limesdr and gr-rds
    
        installed libraries during gr-osmosdr install
    
            libgnuradio-audio.so.3.8.1
    
            libgnuradio-blocks.so.3.8.1
    
            libgnuradio-pmt.so.3.8.1
    
            libgnuradio-runtime.so.3.8.1
    
            libgnuradio-fcdproplus.so.3.8.0
    
            libgnuradio-iqbalance.so.3.8.0
    
            ilbgnuradio-uhd.so.3.8.0
    
            ibgnuradio-fosphor.so.3.8.0
    
        installed libraries during gr-rds install
    
            libgnuradio-analog.so.3.8.1
    
            libgnuradio-digital.so.3.8.1
    
            libgnuradio-filter.so.3.8.1
    
    
    I also notice that gr-osmosdr and gr-limesdr depend on
    libgnuradio-xxx >= 3.8.1.0~rc1. So I don't understand why 3.8.1
    libraries have been installed after 3.8.2 libraries

Here are my questions:

• Is the existence of these multiple libraries versions the cause of errors?
  
• Could someone please provide some link to PPA or source to compile (for gr-osmosdr and gr-limesdr) which are compatible with GNURadio 3.8.2.0?
• Should I reverse to GNURadio 3.8.1 using PPA  http://ppa.launchpad.net/gnuradio/gnuradio-releases/ubuntu?

    Regards, Christophe