rational resampler fractional bandwidth error

[Jason Matusiak]

It has been a while since I have worked with GNUradio, but I am poking around with it again and having some issues.  I am currently using v3.8 on an Ubuntu machine.

I was trying to get a custom flowgraph to work and ran up against an error for the rational resampler.  I then pulled out the  fm_rds_alternate.grc example from gr-rds and found the exact same issue.  Basically, if I use the stock flowgraph, when I try to run it, I get the following error:

Traceback (most recent call last):

  File "/opt/gnuradio/v3.8/src/gr-rds/examples/fm_rds_alternate.py", line 784, in <module>

    main()

  File "/opt/gnuradio/v3.8/src/gr-rds/examples/fm_rds_alternate.py", line 760, in main

    tb = top_block_cls()

  File "/opt/gnuradio/v3.8/src/gr-rds/examples/fm_rds_alternate.py", line 548, in __init__

    fractional_bw=0)

  File "/opt/gnuradio/v3.8/lib/python3/dist-packages/gnuradio/filter/rational_resampler.py", line 150, in __init__

    interpolation, decimation, taps, fractional_bw)

  File "/opt/gnuradio/v3.8/lib/python3/dist-packages/gnuradio/filter/rational_resampler.py", line 113, in __init__

    taps = design_filter(interpolation, decimation, fractional_bw)

  File "/opt/gnuradio/v3.8/lib/python3/dist-packages/gnuradio/filter/rational_resampler.py", line 46, in design_filter

    raise ValueError("Invalid fractional_bandwidth, must be in (0, 0.5)")

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

>>> Done (return code 1)

Did something maybe change with the rational resampler and I need to update older flowgraphs?  Using a value of 0.4 allows it to run, but I am not sure if that is an acceptable value when it was previously set to zero (it would appear).