# GRC now confused about source/sink sizes

**URL:** <https://www.ruby-forum.com/t/grc-now-confused-about-source-sink-sizes/232354>\
**Category:** GNU Radio\
**Created:** [October 5, 2014, 6:53am UTC](https://www.ruby-forum.com/t/grc-now-confused-about-source-sink-sizes/232354 "2014-10-05T06:53:42Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [October 5, 2014, 6:53am UTC](https://www.ruby-forum.com/t/grc-now-confused-about-source-sink-sizes/232354/1 "2014-10-05T06:53:42Z")

</div>

[This is with latest master: 3.7.6git-57-g029079cf]

If you pull simple\_ra from cgran:

svn co [https://www.cgran.org/svn/projects/simple\_ra](https://www.cgran.org/svn/projects/simple_ra)

go into simple\_ra/trunk

And do a “make”

It will fail.

If you then:

PYTHONPATH=.:$PYTHONPATH  
export PYTHONPATH

(add ‘.’ so that it will correctly pick up simple\_ra\_utils)

then manually pull simple\_ra\_receiver.grc into gnuradio-companion,  
you’ll find that it will error claiming that a virtual source of size 0  
is connecting  
to sink of some other size. Open the offending block, click “OK”,  
and the error leaves. Exactly _which_ source/sink blocks are involved  
seems  
to be somewhat non-deterministic. But when you open the block, and  
“OK”, I guess it re-evaluates the dependency graph or something, and  
everything is just fine from that point onwards, then just build and  
save, and you’re on your merry way.

But this prevents the makefile from working, since grcc is just  
non-deterministically erroring-out.

I was seeing similar behaviour with tnt’s eval-cache patch, so I wonder  
if this is similar, but due to Sebastian’s recent work on GRC?