[Discuss-gnuradio] possible bug in tag->srcid processing

This issue is for GNURadio 3.7.4 on Ubuntu 14.04 and gcc 4.8.2, swig 2.0.11.

I have a simple GRC flow graph consisting of a vector source -> throttle -> tag debug.  Vector source params:

Vector:[1, ] * 100
Tags: [python_to_tag({'offset': 0, 'key': pmt.to_pmt('PDU'), 'value': pmt.to_pmt(2.3), 'srcid': pmt.to_pmt('blocks_vector_source_x_0')}),]

Output looks like:

----------------------------------------------------------------------
Tag Debug: Debug tags
Input Stream: 00
  Offset: 0  Source: n/a     Key: PDU   Value: 2.3
----------------------------------------------------------------------

The srcid appears to be correctly translated to a pmt symbol in python and set in python_to_tag, but in tag_debug_impl.cc:126 the type check

(pmt::is_symbol(d_tags_itr->srcid) ? pmt::symbol_to_string(d_tags_itr->srcid) : "n/a")

is false.  Within the debugger the test pmt::is_bool(d_tags_itr->srcid) returns true.  I am not sure how to further debug this problem.  Is this a swig issue?  Am I making a mistake in the tag creation?

Appreciate any suggestions.

Jared.