title: osx - C++14 compiler not detected, multiple versions of gcc when compiling graph-tool in anaconda
body: <p><strong>My ultimate goal</strong> is to get python package <code>graph_tool</code> working on my system and also on ipynb if possible. I have already <code>brew install graph-tool</code>, <a href="https://git.skewed.de/count0/graph-tool/wikis/installation-instructions#macos-x" rel="nofollow noreferrer">as indicated here</a>, but that's still insufficient.</p>
  
  <p>So I follow <a href="https://gist.github.com/dlozeve/ed59bba8bc8cb9b21e2af36cc9766938" rel="nofollow noreferrer">conda instructions here</a>, and I make decent progress, until I encounter a compiler issue with the configuration.</p>
  
  <pre><code>$ conda create -n py36env python=3.6.3 anaconda
  (py36env) $ conda install -c conda-forge cgal 
  ... and so forth with the other required libraries
  
  (py36env) Tams-MacBook-Pro:graph-tool-2.25 tamtam$ ./configure --prefix=/Users/tamtam/anaconda3/envs/py36env/ --with-python-module-path=/Users/tamtam/anaconda3/envs/py36env/lib/python3.6/site-packages
  .
  .
  .
  checking whether g++ supports C++14 features by default... no
  checking whether g++ supports C++14 features with -std=gnu++14... no
  checking whether g++ supports C++14 features with -std=gnu++1y... no
  configure: error: *** A compiler with support for C++14 language features is required.
  </code></pre>
  
  <p>I'm not very familiar with compiler things, but I check my system as follows:</p>
  
  <pre><code>(py36env) Tams-MacBook-Pro:graph-tool-2.25 tamtam$ conda list | grep gcc
  gcc                       4.8.5                         8
  </code></pre>
  
  <p>And outside of the conda env:  </p>
  
  <pre><code>$ gcc -v
  Using built-in specs.
  COLLECT_GCC=gcc
  COLLECT_LTO_WRAPPER=/Users/tamtam/anaconda3/envs/py36env/bin/../libexec/gcc/x86_64-apple-darwin11.4.2/4.8.5/lto-wrapper
  Target: x86_64-apple-darwin11.4.2
  Configured with: ./configure --prefix=/Users/ray/mc-x64-3.5/conda-bld/gcc-4.8_1477649012852/
  Thread model: posix
  gcc version 4.8.5 (GCC)
  </code></pre>
  
  <p>And with Homebrew</p>
  
  <pre><code>$ brew list --versions | grep gcc
  gcc 7.1.0 7.2.0
  $ /usr/local/bin/gcc-7 --version
  gcc-7 (Homebrew GCC 7.2.0) 7.2.0
  $ echo $PATH
  /Users/tamtam/anaconda3/bin:/Users/tamtam/anaconda/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/TeX/texbin
  </code></pre>
  
  <p><br />
  <strong>So my questions are: EDITS INCLUDED</strong> <br />
  1) What's the difference between the <code>conda</code> <code>gcc 4.8.5</code> and <code>Homebrew</code> <code>gcc 7.2</code> on my system? I'm confused because they're each up-to-date packages. <br />
  EDIT: Nowhere online that I perused explicitly states this, but I am understanding (aka educated guess bc it's 3am and I need sleep) <code>conda gcc 4.8.5</code> to just be equivalent to <code>brew gcc 4.8.5</code>, and that Anaconda is just way behind on developing an 'official' gcc supporting C++14. In the meantime I <code>conda install -c salford_systems gcc-5</code> and <code>./configure</code> seems to find itself a C++14 compiler. YAY (but this also led me to a new problem T.B.A.)<br />
  NOTE: I had also tried running the <code>./configure</code> file with both <code>conda gcc 4.8.5</code> and <code>brew gcc 7.2.0</code> (switching of default gcc compiler <a href="https://stackoverflow.com/questions/28970935/osx-replace-gcc-version-4-2-1-with-4-9-installed-via-homebrew">guided here</a>), but still same error of <code>./configure</code> not finding C++14 compile (so ignore this)
  <br />
  <br />
  2) I also have Xcode 8.3.3 that also comes with clang, which is what gcc is symlinked to... ?? No idea about the setup/relation 
  <br />
  <br />
  3) How can I adjust my system (for example, paths) so that the configuration process will detect a C++14 compiler? EDIT: resolved per 1) <br /></p>