# Uhd\_fft segfault

**URL:** <https://www.ruby-forum.com/t/uhd-fft-segfault/234218>\
**Category:** GNU Radio\
**Created:** [February 16, 2015, 9:30pm UTC](https://www.ruby-forum.com/t/uhd-fft-segfault/234218 "2015-02-16T21:30:48Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**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:** [February 16, 2015, 9:30pm UTC](https://www.ruby-forum.com/t/uhd-fft-segfault/234218/1 "2015-02-16T21:30:48Z")

</div>

Hi,

I’m new to SDR and gnuradio and trying to get started with an USRP B200  
and gnuradio on ubuntu 14.04.  
I’m using pybombs (up-to-date) for building. Building succeeds but i get  
a segfault when running uhd\_fft.  
The backtrace is below.

I checked if the correct libuhd was being used (with ldd),instead of an  
old version from an ubuntu package.  
I also tried uhd\_find\_devices (which uses pure uhd if i’m correct,  
without gnuradio?), this works fine.  
Running “pybombs verify gnuradio” results in:  
The following tests FAILED:  
183 - qa\_uhd (Failed)  
192 - qa\_fcd (Failed)  
Errors while running CT

Running gnuradio/gr-uhd/python/uhd/qa\_uhd.py in gdb segfaults with a  
similar backtrace as well.  
Finally, i tried changing the gnuradio recipe to use the maint branch  
instead of master.  
Rebuilding (after cleaning the build dir) results in the same situation  
however.

I don’t know where to look next. Did anyone experience the same problem?  
Thanks for any pointers!

(gdb) bt  
#0 0x000000000001e626 in ?? ()  
#1 0x00007ffff079d3a0 in strstr (\_\_needle=0x7ffff082bfca "swig\_ptr: ",  
\_\_haystack=0xd9398 \<error: Cannot access memory at address 0xd9398\>) at  
/usr/include/string.h:337  
#2 SWIG\_Python\_FixMethods (methods=0x7ffff0a57380 ,  
const\_table=0x7ffff0a5d920 \<swig\_const\_table\>, types=0x7ffff0a5d980  
\<swig\_types\>,  
types\_initial=0x7ffff0a55a20 \<swig\_type\_initial\>) at  
/home/glenn/projects/pybombs/src/gnuradio/build/gr-uhd/swig/uhd\_swigPYTHON\_wrap.cxx:47200  
#3 init\_uhd\_swig () at  
/home/glenn/projects/pybombs/src/gnuradio/build/gr-uhd/swig/uhd\_swigPYTHON\_wrap.cxx:47321  
#4 0x00000000004268bc in \_PyImport\_LoadDynamicModule  
(name=0x7ffff1cccd74 “\_uhd\_swig”,  
pathname=0x7fffed3fa48c  
“/home/glenn/bin/gnuradio/lib/python2.7/dist-packages/gnuradio/uhd/\_uhd\_swig.so”,  
fp=) at …/Python/importdl.c:53  
#5 0x00000000005b75d1 in load\_module.39237 (name=,  
fp=, pathname=, type=,  
loader=loader@entry=0x0)  
at …/Python/import.c:1915  
#6 0x000000000046232a in imp\_load\_module.39244 (self=,  
args=) at …/Python/import.c:3182  
#7 0x000000000052c6d5 in call\_function (oparg=,  
pp\_stack=0x7fffffffc170) at …/Python/ceval.c:4020  
#8 PyEval\_EvalFrameEx (f=f@entry=  
Frame 0x7ffff2182a50, for file  
/home/glenn/bin/gnuradio/lib/python2.7/dist-packages/gnuradio/uhd/uhd\_swig.py,  
line 24, in swig\_import\_helper (dirname=\<function at remote  
0x7ffff7f0f578\>, imp=\<module at remote 0x7ffff6b519f0\>, fp=\<file at  
remote 0x7ffff0aa1f60\>,  
pathname=‘/home/glenn/bin/gnuradio/lib/python2.7/dist-packages/gnuradio/uhd/\_uhd\_swig.so’,  
description=(‘.so’, ‘rb’, 3)), throwflag=throwflag@entry=0) at  
…/Python/ceval.c:2666  
#9 0x000000000052cf32 in fast\_function (nk=,  
na=, n=0, pp\_stack=0x7fffffffc2b0, func=\<function at  
remote 0x7fffed3fa398\>)  
at …/Python/ceval.c:4106  
#10 call\_function (oparg=, pp\_stack=0x7fffffffc2b0) at  
…/Python/ceval.c:4041  
#11 PyEval\_EvalFrameEx (f=f@entry=Frame 0x7ffff1c73b00, for file  
/home/glenn/bin/gnuradio/lib/python2.7/dist-packages/gnuradio/uhd/uhd\_swig.py,  
line 28, in (),  
throwflag=throwflag@entry=0) at …/Python/ceval.c:2666  
#12 0x000000000055c594 in PyEval\_EvalCodeEx (co=0x7fffed40a9b0,  
globals=, locals=, args=,  
argcount=,  
kws=, kwcount=0, defs=0x0, defcount=0, closure=0x0)  
at …/Python/ceval.c:3252  
#13 0x00000000005b7392 in PyEval\_EvalCode (co=,  
globals=, locals=) at  
…/Python/ceval.c:667  
#14 0x00000000005b744a in PyImport\_ExecCodeModuleEx  
(name=name@entry=0xdf9060 “gnuradio.uhd.uhd\_swig”, co=co@entry=\<code at  
remote 0x7fffed40a9b0\>,  
pathname=pathname@entry=0xa0f170  
“/home/glenn/bin/gnuradio/lib/python2.7/dist-packages/gnuradio/uhd/uhd\_swig.pyc”)  
at …/Python/import.c:709  
#15 0x0000000000579f0f in load\_source\_module.39194  
(name=name@entry=0xdf9060 “gnuradio.uhd.uhd\_swig”,  
pathname=0xa0f170  
“/home/glenn/bin/gnuradio/lib/python2.7/dist-packages/gnuradio/uhd/uhd\_swig.pyc”,

```
 pathname@entry=0xa72300

```

“/home/glenn/bin/gnuradio/lib/python2.7/dist-packages/gnuradio/uhd/uhd\_swig.py”,  
fp=) at …/Python/import.c:1099  
#16 0x00000000005b7541 in load\_module.39237 (name=name@entry=0xdf9060  
“gnuradio.uhd.uhd\_swig”, fp=,  
pathname=pathname@entry=0xa72300  
“/home/glenn/bin/gnuradio/lib/python2.7/dist-packages/gnuradio/uhd/uhd\_swig.py”,  
type=, loader=)  
at …/Python/import.c:1906  
#17 0x000000000055d3a3 in import\_submodule.39248 (mod=mod@entry=\<module  
at remote 0x7ffff1c8aa98\>, subname=subname@entry=0xdf906d “uhd\_swig”,  
fullname=0xdf9060 “gnuradio.uhd.uhd\_swig”) at  
…/Python/import.c:2700  
#18 0x000000000055d77c in load\_next (mod=\<module at remote  
0x7ffff1c8aa98\>, altmod=None, p\_name=p\_name@entry=0x7fffffffc650,  
buf=buf@entry=0xdf9060 “gnuradio.uhd.uhd\_swig”,  
p\_buflen=p\_buflen@entry=0x7fffffffc660) at …/Python/import.c:2515  
#19 0x000000000055db37 in import\_module\_level.isra.3 (level=-1,  
fromlist=None, globals=, name=0x0) at  
…/Python/import.c:2224  
#20 PyImport\_ImportModuleLevel (name=, globals=, locals=, fromlist=None, level=-1) at  
…/Python/import.c:2288  
#21 0x00000000004755e7 in builtin\_\_\_import\_\_.32997 (self=, args=, kwds=) at  
…/Python/bltinmodule.c:49  
#22 0x00000000004da20b in PyObject\_Call (kw=0x0,  
arg=(‘uhd\_swig’, {‘\_prepare\_uhd\_swig’: \<function at remote  
0x7ffff0adf2a8\>, ‘ **builtins** ’: {‘bytearray’: \<type at remote  
0x9166a0\>, ‘IndexError’: \<type at remote 0x919900\>, ‘all’: , ‘help’: \<\_Helper at remote 0x7ffff7e7d290\>, ‘vars’:  
, ‘SyntaxError’: \<type at remote 0x91b9e0\>,  
‘unicode’: \<type at remote 0x91dc80\>, ‘UnicodeDecodeError’: \<type at  
remote 0x91a920\>, ‘memoryview’: \<type at remote 0x90dae0\>, ‘isinstance’:  
, ‘copyright’:  
\<\_Printer(\_Printer\_\_data=‘Copyright (c) 2001-2014 Python Software  
Foundation.\nAll Rights Reserved.\n\nCopyright (c) 2000 [BeOpen.com](http://BeOpen.com).\nAll  
Rights Reserved.\n\nCopyright (c) 1995-2001 Corporation for National  
Research Initiatives.\nAll Rights Reserved.\n\nCopyright (c) 1991-1995  
Stichting Mathematisch Centrum, Amsterdam.\nAll Rights Reserved.’,  
\_Printer\_\_lines=None, \_Printer\_\_name=‘copyright’, \_Printer\_\_dirs=(),  
\_Printer\_\_files=(…)) at remote 0x7ffff7e7d590\>, ‘NameError’: \<type at  
remote 0x91bd20\>, ‘BytesWarn…(truncated), func=) at …/Objects/abstract.c:2529  
#23 PyEval\_CallObjectWithKeywords (func=func@entry=,  
arg=arg@entry=(‘uhd\_swig’, {’\_prepare\_uhd\_swig’: \<function at  
remote 0x7ffff0adf2a8\>, ‘ **builtins** ’: {‘bytearray’: \<type at remote  
0x9166a0\>, ‘IndexError’: \<type at remote 0x919900\>, ‘all’: , ‘help’: \<\_Helper at remote 0x7ffff7e7d290\>, ‘vars’:  
, ‘SyntaxError’: \<type at remote 0x91b9e0\>,  
‘unicode’: \<type at remote 0x91dc80\>, ‘UnicodeDecodeError’: \<type at  
remote 0x91a920\>, ‘memoryview’: \<type at remote 0x90dae0\>, ‘isinstance’:  
, ‘copyright’:  
\<\_Printer(\_Printer\_\_data=‘Copyright (c) 2001-2014 Python Software  
Foundation.\nAll Rights Reserved.\n\nCopyright (c) 2000 [BeOpen.com](http://BeOpen.com).\nAll  
Rights Reserved.\n\nCopyright (c) 1995-2001 Corporation for National  
Research Initiatives.\nAll Rights Reserved.\n\nCopyright (c) 1991-1995  
Stichting Mathematisch Centrum, Amsterdam.\nAll Rights Reserved.’,  
\_Printer\_\_lines=None, \_Printer\_\_name=‘copyright’, \_Printer\_\_dirs=(),  
\_Printer\_\_files=(…)) at remote 0x7ffff7e7d590\>, ‘NameError’: \<type at  
remote

---

<div class="post-metadata">

**Author:** ![Ergeerts\_Glenn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/b5e925/32.png) [@Ergeerts\_Glenn](https://www.ruby-forum.com/u/Ergeerts_Glenn)\
**Post date:** [February 16, 2015, 9:41pm UTC](https://www.ruby-forum.com/t/uhd-fft-segfault/234218/2 "2015-02-16T21:41:21Z")

</div>

Those swig traces are hard to parse, but you might have to rebuild GNU  
Radio against the current UHD build. Did you install both via Pybombs?

M

---

<div class="post-metadata">

**Author:** ![Ergeerts\_Glenn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/b5e925/32.png) [@Ergeerts\_Glenn](https://www.ruby-forum.com/u/Ergeerts_Glenn)\
**Post date:** [February 16, 2015, 9:49pm UTC](https://www.ruby-forum.com/t/uhd-fft-segfault/234218/3 "2015-02-16T21:49:30Z")

</div>

yes i did, “pybombs list” shows this:

```
              gnuradio installed inventory

```

fc7861ac029a4297df5a0b1159cb07f922670054  
git://http://www.gnuradio.org/git/gnuradio.git  
uhd installed inventory  
7d97ab60012b99ed92fb122a3a68d68515a404fa  
git://https://github.com/EttusResearch/uhd.git

---

<div class="post-metadata">

**Author:** ![Ergeerts\_Glenn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/b5e925/32.png) [@Ergeerts\_Glenn](https://www.ruby-forum.com/u/Ergeerts_Glenn)\
**Post date:** [February 17, 2015, 1:39am UTC](https://www.ruby-forum.com/t/uhd-fft-segfault/234218/4 "2015-02-17T01:39:00Z")

</div>

I once had an OpenGL issue mess with uhd\_fft. If you run ‘glxgears’ from  
a terminal does it work and do you get a normal frame rate (30+ fps, I  
get up to 60). My fix was installing proper video card drivers. Just a  
thought.

Rich

Sent from my iPhone

---

<div class="post-metadata">

**Author:** ![Ergeerts\_Glenn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/b5e925/32.png) [@Ergeerts\_Glenn](https://www.ruby-forum.com/u/Ergeerts_Glenn)\
**Post date:** [February 17, 2015, 12:06pm UTC](https://www.ruby-forum.com/t/uhd-fft-segfault/234218/5 "2015-02-17T12:06:20Z")

</div>

glxgears shows 60 fps (using binary nvidia driver).

just to be complete: i had a linker error first when building gnuradio  
using pybombs, which i didn’t yet mention.  
The output is shown below. It seemed not critical to me since it happens  
when linking an example.  
I ‘solved’ it by commenting the “add\_subdirectory(examples/c++)” in  
gr-uhd/CMakeLists.txt .  
Maybe i made a wrong assumption and could this be causing the problem  
mentioned before?  
Or maybe this error can be helpfull for diagnosing the issue?

Linking CXX executable tags\_demo  
[45%] Built target pygen\_gr\_uhd\_swig\_c9605  
[46%] Built target \_uhd\_swig  
Scanning dependencies of target \_vocoder\_swig  
[46%] Built target pygen\_gr\_vocoder\_swig\_aa5c8  
[66%] Built target gnuradio-blocks  
[66%] Built target pygen\_gr\_fcd\_swig\_f8a01  
[66%] [66%] Built target pygen\_gr\_wavelet\_swig\_e3597  
Building CXX object  
gr-vocoder/swig/CMakeFiles/\_vocoder\_swig.dir/vocoder\_swigPYTHON\_wrap.cxx.o  
[66%] Built target \_wxgui\_swig  
[66%] Built target pygen\_gr\_wxgui\_swig\_bf89e  
[66%] Built target gr\_runtime\_test  
[66%] Built target gr\_pmt\_test  
Scanning dependencies of target test-gr-blocks  
[66%] Built target pmt\_swig  
Scanning dependencies of target \_blocks\_swig0  
/home/glenn/bin/gnuradio/lib/libuhd.so: undefined reference to  
`libusb\_error\_name’  
collect2: error: ld returned 1 exit status  
make[2]: \*\*\* [gr-uhd/examples/c++/tags\_demo] Error 1  
make[1]: \*\*\* [gr-uhd/examples/c++/CMakeFiles/tags\_demo.dir/all] Error 2  
make[1]: \*\*\* Waiting for unfinished jobs…  
[66%] [66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/test\_gr\_blocks.cc.o  
Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_gr\_block.cc.o  
[66%] Building CXX object  
gr-blocks/swig/CMakeFiles/\_blocks\_swig0.dir/blocks\_swig0PYTHON\_wrap.cxx.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_gr\_top\_block.cc.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_gr\_hier\_block2.cc.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_gr\_hier\_block2\_derived.cc.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_blocks.cc.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_block\_tags.cc.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_rotator.cc.o  
Linking CXX executable test-gr-blocks  
[66%] Built target test-gr-blocks  
Linking CXX shared module \_vocoder\_swig.so  
[66%] Built target \_vocoder\_swig  
Linking CXX shared module \_blocks\_swig0.so  
[66%] Built target \_blocks\_swig0  
make: \*\*\* [all] Error 2  
Build failed. See output above for error messages.

---

<div class="post-metadata">

**Author:** ![Ergeerts\_Glenn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/b5e925/32.png) [@Ergeerts\_Glenn](https://www.ruby-forum.com/u/Ergeerts_Glenn)\
**Post date:** [February 17, 2015, 3:59pm UTC](https://www.ruby-forum.com/t/uhd-fft-segfault/234218/6 "2015-02-17T15:59:13Z")

</div>

On 02/17/2015 09:35 AM, Tom R. wrote:

> ```
> when linking an example.
> Scanning dependencies of target _vocoder_swig
> Scanning dependencies of target test-gr-blocks
> gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/test_gr_blocks.cc.o
> [66%] Building CXX object
> [66%] Built target _blocks_swig0
> 
> ```
> 
> rnd uhd" and then rerun “./pybombs install uhd”. Then do the same for  
> gnuradio and see if that completes.
> 
> If you have /any/ error when building GNU Radio, this suggests a  
> deeper problem.
> 
> Tom

For B2xx support, you need a version of libusb that has  
libusb\_error\_name() – older versions of the library don’t have this  
API, and that’s why  
you’re getting the linker error.

---

<div class="post-metadata">

**Author:** ![Ergeerts\_Glenn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/b5e925/32.png) [@Ergeerts\_Glenn](https://www.ruby-forum.com/u/Ergeerts_Glenn)\
**Post date:** [February 17, 2015, 3:38pm UTC](https://www.ruby-forum.com/t/uhd-fft-segfault/234218/7 "2015-02-17T15:38:59Z")

</div>

On Tue, Feb 17, 2015 at 6:04 AM, Ergeerts Glenn \<  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote:

> Or maybe this error can be helpfull for diagnosing the issue?  
> Building CXX object  
> collect2: error: ld returned 1 exit status  
> gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_gr\_top\_block.cc.o  
> Linking CXX executable test-gr-blocks  
> [66%] Built target test-gr-blocks  
> Linking CXX shared module \_vocoder\_swig.so  
> [66%] Built target \_vocoder\_swig  
> Linking CXX shared module \_blocks\_swig0.so  
> [66%] Built target \_blocks\_swig0  
> make: \*\*\* [all] Error 2  
> Build failed. See output above for error messages.

Yes, this is definitely a problem that is likely related to your  
original  
question. This error here is showing an issue with libusb and libuhd,  
which  
would need to work together for you to run uhd\_fft. It looks like  
something  
is confused in your build of UHD with regards to USB support. I would  
try  
reinstalling UHD. Remove it with “./pybombs rnd uhd” and then rerun  
“./pybombs install uhd”. Then do the same for gnuradio and see if that  
completes.

If you have /any/ error when building GNU Radio, this suggests a deeper  
problem.

Tom

---

<div class="post-metadata">

**Author:** ![Ergeerts\_Glenn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/b5e925/32.png) [@Ergeerts\_Glenn](https://www.ruby-forum.com/u/Ergeerts_Glenn)\
**Post date:** [February 17, 2015, 9:05pm UTC](https://www.ruby-forum.com/t/uhd-fft-segfault/234218/8 "2015-02-17T21:05:19Z")

</div>

i have libusb-1.0-0-dev version 1.0.17-1ubuntu2 installed.  
However, doing ldd on libuhd.so showed that  
/usr/local/lib/libusb-1.0.so.0 was used instead of the version from  
/usr/lib/ .  
I’m not sure how it came there, i suspect from a PPA package i tried  
installing before reverting to pybombs.  
After removing this file ldd now pick the correct libusb and gnuradio  
builds fine!  
I have not been able to test it with the USRP connected but uhd\_fft does  
not segfaults anymore so it seems fixed.

Thanks for the help and sorry for not providing this information up  
front!

On 02/17/2015 03:57 PM, Marcus D. Leech wrote:  
On 02/17/2015 09:35 AM, Tom R. wrote:  
On Tue, Feb 17, 2015 at 6:04 AM, Ergeerts Glenn  
\<[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\>  
wrote:  
glxgears shows 60 fps (using binary nvidia driver).

just to be complete: i had a linker error first when building gnuradio  
using pybombs, which i didn’t yet mention.  
The output is shown below. It seemed not critical to me since it happens  
when linking an example.  
I ‘solved’ it by commenting the “add\_subdirectory(examples/c++)” in  
gr-uhd/CMakeLists.txt .  
Maybe i made a wrong assumption and could this be causing the problem  
mentioned before?  
Or maybe this error can be helpfull for diagnosing the issue?

Linking CXX executable tags\_demo  
[45%] Built target pygen\_gr\_uhd\_swig\_c9605  
[46%] Built target \_uhd\_swig  
Scanning dependencies of target \_vocoder\_swig  
[46%] Built target pygen\_gr\_vocoder\_swig\_aa5c8  
[66%] Built target gnuradio-blocks  
[66%] Built target pygen\_gr\_fcd\_swig\_f8a01  
[66%] [66%] Built target pygen\_gr\_wavelet\_swig\_e3597  
Building CXX object  
gr-vocoder/swig/CMakeFiles/\_vocoder\_swig.dir/vocoder\_swigPYTHON\_wrap.cxx.o  
[66%] Built target \_wxgui\_swig  
[66%] Built target pygen\_gr\_wxgui\_swig\_bf89e  
[66%] Built target gr\_runtime\_test  
[66%] Built target gr\_pmt\_test  
Scanning dependencies of target test-gr-blocks  
[66%] Built target pmt\_swig  
Scanning dependencies of target \_blocks\_swig0  
/home/glenn/bin/gnuradio/lib/libuhd.so: undefined reference to  
`libusb\_error\_name’  
collect2: error: ld returned 1 exit status  
make[2]: \*\*\* [gr-uhd/examples/c++/tags\_demo] Error 1  
make[1]: \*\*\* [gr-uhd/examples/c++/CMakeFiles/tags\_demo.dir/all] Error 2  
make[1]: \*\*\* Waiting for unfinished jobs…  
[66%] [66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/test\_gr\_blocks.cc.o  
Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_gr\_block.cc.o  
[66%] Building CXX object  
gr-blocks/swig/CMakeFiles/\_blocks\_swig0.dir/blocks\_swig0PYTHON\_wrap.cxx.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_gr\_top\_block.cc.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_gr\_hier\_block2.cc.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_gr\_hier\_block2\_derived.cc.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_blocks.cc.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_block\_tags.cc.o  
[66%] Building CXX object  
gr-blocks/lib/CMakeFiles/test-gr-blocks.dir/qa\_rotator.cc.o  
Linking CXX executable test-gr-blocks  
[66%] Built target test-gr-blocks  
Linking CXX shared module \_vocoder\_swig.so  
[66%] Built target \_vocoder\_swig  
Linking CXX shared module \_blocks\_swig0.so  
[66%] Built target \_blocks\_swig0  
make: \*\*\* [all] Error 2  
Build failed. See output above for error messages.

Yes, this is definitely a problem that is likely related to your  
original question. This error here is showing an issue with libusb and  
libuhd, which would need to work together for you to run uhd\_fft. It  
looks like something is confused in your build of UHD with regards to  
USB support. I would try reinstalling UHD. Remove it with “./pybombs rnd  
uhd” and then rerun “./pybombs install uhd”. Then do the same for  
gnuradio and see if that completes.

If you have /any/ error when building GNU Radio, this suggests a deeper  
problem.

Tom

For B2xx support, you need a version of libusb that has  
libusb\_error\_name() – older versions of the library don’t have this  
API, and that’s why  
you’re getting the linker error.

On 02/17/2015 01:37 AM, Richard B. wrote:

> > ```
> > gnuradio installed inventory
> > 
> > ```
> > 
> > > > Running gnuradio/gr-uhd/python/uhd/qa\_uhd.py in gdb segfaults with a  
> > > > (gdb) bt

/home/glenn/projects/pybombs/src/gnuradio/build/gr-uhd/swig/uhd\_swigPYTHON\_wrap.cxx:47321

> > > > args=) at ../Python/import.c:3182  
> > > > ../Python/ceval.c:2666  
> > > > #12 0x000000000055c594 in PyEval\_EvalCodeEx (co=0x7fffed40a9b0,

“/home/glenn/bin/gnuradio/lib/python2.7/dist-packages/gnuradio/uhd/uhd\_swig.pyc”)

> > > > “gnuradio.uhd.uhd\_swig”, fp=,  
> > > > p\_buflen=p\_buflen@entry=0x7fffffffc660) at ../Python/import.c:2515  
> > > > 0x7ffff0adf2a8\>, ‘ **builtins** ’: {‘bytearray’: \<type at remote  
> > > > Stichting Mathematisch Centrum, Amsterdam.\nAll Rights Reserved.',  
> > > > , ‘SyntaxError’: \<type at remote 0x91b9e0\>,  
> > > > remote  
> > > > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio)
> > 
> > * * *
> > 
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