No audio with Si470x on Ubuntu 20.04

[mvglasow]

To reproduce:

1. Use Ubuntu 20.04
2. Plugin in a Si470x USB tuner
3. Launch RDS Surveyor, choosing the appropriate input source.

Behavior observed:

I can change frequencies and view RDS data, but there is no audio (audio button is grayed out).

Behavior expected:

Audio is available and can be enabled/disabled with the audio button.

Versions:

cf1e37b on Ubuntu 20.04

Further information:

Audio worked up to and including Ubuntu 18.04, thus I suppose it is some OS incompatibility. Didn’t get to grab a stack trace yet (I remember there was an exception), will do that as soon as I get to it. RTL SDR audio still works; it is only the combination of the Si470x and Ubuntu 20.04 that is affected.

[mvglasow]

Totally forgot about this, plugged in the SDR and launched RDS Surveyor, and everything works. Either there was a bug in the OS, or a sporadic failure, or I granted myself a missing permission as a side effect of some other fix (though that is highly speculative).