fcdp-tetra_demod.py -D hw:1 -o /dev/stdout | ./170913/src/float_to_bits /dev/stdin /dev/stdout | ./170913/src/tetra-rx /dev/stdin
Traceback (most recent call last):
  File "./170913/src/demod/python/fcdp-tetra_demod.py", line 5, in <module>
    from gnuradio import gr, gru, audio, eng_notation, blks2, optfir
ImportError: cannot import name blks2

In Gnuradio 3.7

Block blk2 has been replaced by digital - if the block replaced then the following error occured :

then optfir can't be opened --> optfir is reference to optfir.py or optfir.pyc ?

If I remove optfir , I have error with sound card access and this :

in line 83

    tb = my_top_block(options)is also with erreur 

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