[Discuss-gnuradio] AttributeError: 'function' object has no attribute 'to_basic_block' ? (GR 3.7.0)

[Monahan-Mitchell, Tim]

I've stepped up to GR 3.7.0, re-used gr_modtool to freshly re-create my OOT 
module, everything builds, tests, installs OK. GRC has my OOT blocks listed and 
I can put them on my flowgraph.

One of my OOT blocks is a function that takes in shorts and outputs shorts (a 
1-to-2 interpolator).

I have a simple flowgraph created in GRC:   File Source -> My block -> File 
sync .

GRC is happy until I run the flowgraph, and I get this:

Executing: "<....> /top_block.py"

Traceback (most recent call last):
  File "<....> /top_block.py", line 54, in <module>
    tb = top_block()
  File "<....> /top_block.py", line 39, in __init__
    self.connect((self.my_block_s_to_s_0, 0), (self.blocks_file_sink_0, 0))
  File "/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top_block.py", line 
130, in connect
    self._connect(points[i-1], points[i])
  File "/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top_block.py", line 
141, in _connect
    self._tb.primitive_connect(src_block.to_basic_block(), src_port,
AttributeError: 'function' object has no attribute 'to_basic_block'

Platform: Ubuntu 12.04 on VMware x86

The File Source and Sink blocks came from the "File Operators" collection in 
GRC.

If I delete my block from the middle, leaving File Source -> File Sink, it runs 
OK.

Any ideas? This worked  fine when the system was GR 3.6.4.2 based.

Thanks,
Tim