title: Installing Orange3 in Anaconda: Mismatching g++ and libstdc++
body: <p>I'm running Fedora 25, which comes with <code>gcc/g++/libstdc++</code> version 6.3.1.
  I'm also running Anaconda version 4.3.1, which comes with <code>libstdc++ 6.0.19</code>.</p>
  
  <p>When I install Orange3 under Anaconda (by saying "pip install orange3"), some files are compiled with Fedoras g++, but linked against Anacondas libstdc++:</p>
  
  <p>Note the third line of the output:</p>
  
  <pre><code>$ ldd ~/anaconda3/lib/python3.6/site-packages/Orange/widgets/utils/_grid_density.cpython-36m-x86_64-linux-gnu.so
  linux-vdso.so.1 (0x00007ffe9b5a2000)
  libpython3.6m.so.1.0 =&gt; /home/marhoy/anaconda3/lib/libpython3.6m.so.1.0 (0x00007efc3a6ef000)
  libstdc++.so.6 =&gt; /home/marhoy/anaconda3/lib/libstdc++.so.6 (0x00007efc3a3d9000)
  libm.so.6 =&gt; /lib64/libm.so.6 (0x00007efc3a0ad000)
  libgcc_s.so.1 =&gt; /home/marhoy/anaconda3/lib/libgcc_s.so.1 (0x00007efc39e97000)
  libpthread.so.0 =&gt; /lib64/libpthread.so.0 (0x00007efc39c79000)
  libc.so.6 =&gt; /lib64/libc.so.6 (0x00007efc398b1000)
  libdl.so.2 =&gt; /lib64/libdl.so.2 (0x00007efc396ad000)
  libutil.so.1 =&gt; /lib64/libutil.so.1 (0x00007efc394aa000)
  librt.so.1 =&gt; /lib64/librt.so.1 (0x00007efc392a2000)
  /lib64/ld-linux-x86-64.so.2 (0x000055a3c43d1000)
  </code></pre>
  
  <p>This causes problems, as there are differences between 6.3.1 and 6.0.19. So when I try to use the scatter-plot widget, I get:</p>
  
  <p><code>_grid_density.cpython-36m-x86_64-linux-gnu.so: undefined symbol: __cxa_throw_bad_array_new_length</code></p>
  
  <p>If I LD_PRELOAD Fedoras libstdc++, everything seems to work fine.
  And if I install Orange3 outside of Anaconda (by using pip3 install --user orange3), it also works.</p>
  
  <p>The reason I'm not installing Orange3 from the conda repository is because it is outdated.</p>
  
  <p>So: <strong>How can I make the Orange-files link against my Fedora libstdc++ ?</strong></p>