FEC GnuRadio 3.7.8rc1 Error

Ubuntu 14.04 64-bit
Gnuradio 3.7.8rc1

I am running this flowgraph “fecapi_async_to_stream.grc” that comes with
gr-fec. After running for a while following error always show up

DEBUG: 16384, 560, 272
DEBUG: 16384, 560, 272
FATAL: Missing a required length tag on port 0 at item #14965440
thread[thread-per-block[7]: <block fec_tagged_decoder (7)>]: Missing

The only thing that changes is the item#.
Testing further …

On Wed, Aug 5, 2015 at 2:07 AM, bob wole [email protected] wrote:

DEBUG: 16384, 560, 272


You led us down a buggy path on that one. This, I’m pretty sure, is
to Richard B.'s problem for a few weeks ago where adding a time sink
caused problems in his data stream. I have to say, I kind of dismissed
as impossible, but nope, it’s a real problem.

The problem isn’t with the GUI sinks; you can replace them with null
and you get the same problem. It’s a race condition in our tag pruning
method that was changed in 3.7.6. We have a patch that we’re putting in
that will be part of 3.7.8.

The patch goes backwards a bit to how tag pruning was originally done.
However, with the map, we no longer have to restart the iterator at
like we used to, and we can terminate early, so this should still be
faster than the original.