Using gnuradio-3.8.5.0, the fm_demod_stereo_clean.grc flowgraph does not work out of the box; grcc compiles it without complaining but python refuses to run the output script:

ValueError: Invalid fractional_bandwidth, must be in (0, 0.5)

It appears some sort of change happened in gnuradio, and that leaving the Fractional BW fields all blank fixes the problem; I found that fix here: https://www.mail-archive.com/[email protected]/msg73322.html

(I didn't verify all the flowgraphs in this repo, there might be more similar issues).

This is IMHO a bug on gnuradio's side, not on your codebase, but someone else in the future trying your flowgraphs will likely hit the same issue.

While I'm here, thank you for your work, very useful to me.