ChangeLog v3.7.9.1


The following list of people directly contributed code to this release. As an added bonus this is the first contribution for three of these authors!

Closed issues

  • #528
  • #719
  • #768
  • #831
  • #864
  • #868
  • #876
  • #879
  • #882
  • #883


This release includes a number of minor typos and miscellaneous rewording of error messages. The following sections summarize substantial changes.


  • the 'Parser errors' menu item wasn't correctly enabled
  • embedded python blocks: message ports are now optionial and show the correct label
  • custom run command now accounts for filepaths that need escaping
  • virtual sink/source message connections were dropped when opening a flow graph
  • tooltips in block library are truncated if too long
  • not all tooltips in block library were updated after docstring extraction finished
  • some expressions were wrongfully marked invalid after opening a flow graph
  • move random uniform source from analog to waveform generators in GRC

Scheduler and Runtime fixes

A new unit test is available to test a bug reported on stack overflow where blocks (such as the delay block) would drop tags. Paul David stepped in with his first contribution to GNU Radio with a fix.

Fix an issue with flat_flowgraph calculating alignment by misinterpreting units of write and read indices. This was only apparent when these indices are non-zero (a flowgraph has stopped and restarted).

Fix exceptions thrown in hier_block2 constructors.

Check d_ninput_items_required for overflow and shut down if overflow is detected.

Allow hier_block2's to change I/O signature in the constructor, which was previously allowed by the API, but broken.


Use unsigned char rather than char in add_const_bb. This was the legacy behavior with the older add_const_XX and was accidentally replaced with char when replacing the templated version.

Fix vector length units from bytes to number of items in PDU to tagged stream and tagged stream to PDU blocks.


Add a check to the rational resampler to stop working after we've operated on all input items (closed issue #831)

Throw an error when pfb clock sync is given constant taps which results in a derivative of 0 (calculated as NaN). (closed issue #812 and 734). Added a reset_taps function to externally set taps which should be used in place of set_taps

Fix a memory leak in pfb decimator (closed issue #882)


Maximum Deviation parameter for NBFM transmitter exposed to GRC


Change the constellation receiver to inherit from control_loop publically rather than the impl to better support the control port interface. (closed issue #876)


TLC to puncture/depuncture GRC files in gr-fec


Major performance and correctness fixes to gr-zeromq


Fix cross compiling on for 64-bit architectures by not setting DEBIAN, REDHAT, and SLACKWARE. OOT modules created with modtool should update their cmake/Modules/GrPlatform.cmake to support cross 64-bit builds.