Q:

problems building armNN with caffe parser support

I have been at this for quite a while now. Mainly following this tutorial. I have built the dependencies in the versions required by the instructions the 2 main parts beeing boost and caffe (which both entail a host of other dependecies).
I am running the entire thing on a fresh install of Ubuntu 19.10 (setup on a VM specifically for this project).
When i reach building of the armNN library (instructions part "Building the environment", step 4) it fails at linking libarmnn.so at ~45% with the following error output:
/usr/bin/ld: */path/to/boost*/boost_1_64_0/stage/lib/libboost_log.a(attribute_name.o): relocation R_X86_64_PC32 against symbol `_ZTVN5boost16exception_detail19error_info_injectorINS_3log12v2s_mt_posix16limitation_errorEEE' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: bad value
collect2: error: ld returned 1 exit status
make[2]: *** [libarmnn.so.19.11] Error 1
make[1]: *** [CMakeFiles/armnn.dir/all] Error 2
make: *** [all] Error 2

I have built the entire boost library with cxx and c flags -fPIC. I checked specifically for the file in question (using ar -x libboost_log.a 
readelf --relocs attribute_name.o | egrep 'PLT' as suggest in the answer to this question)
Any suggestions on how to deal with this error or tips on what i should look into would be very much appreciated.
Patrick

A:

It took me a couple more attempts and another fresh VM but i finally managed to cross compile the armnn with caffe parsers support (X from ubuntu to android).
If you want to do the same there are a lot of dependencies which you have to compile yourself and you have to take care to compile them all with compatible versions. Which is when you are (like i was 3 weeks ago) just aquainted with all of these libraries in passing easier said then done. 
Here are the most important sources I used to compile:

https://github.com/ARM-software/armnn/blob/master/BuildGuideAndroidNDK.md
https://github.com/ARM-software/armnn/blob/master/BuildGuideCrossCompilation.md
https://github.com/BVLC/caffe/wiki/Commonly-encountered-build-issues

The most important part that I disregarded way to often is that when you are compiling a dependecy and encounter some missing sub dependencies, do NOT fix it the easy way. Installing those using apt which is usually the direct and correct way to solve a missing libraries problem. Later on you will get mismatched library problems.

