title: Installing image pgk on Octave on Mac OS X
body: <p>I installed GNU Octave, version 4.2.0-rc2 on my Mac[0] using Homebrew[1].</p>
  
  <p>But now I tried to install the image pkg[2].</p>
  
  <p>I tried downloading it and then using this line:</p>
  
  <pre><code>"pkg install image-2.6.0.tar.gz"
  </code></pre>
  
  <p>Then I tried installing it with this line of code: </p>
  
  <pre><code>"pkg install -forge image"
  </code></pre>
  
  <p>Both resulted in the following output:</p>
  
  <pre><code>configure: error: *** A compiler with support for C++11 is required
  checking for a sed that does not truncate output... /usr/local/bin/gsed
  checking for octave... /usr/local/Cellar/octave/4.2.0-rc2/bin/octave-4.2.0-rc2
  checking for mkoctfile... /usr/local/Cellar/octave/4.2.0-rc2/bin/mkoctfile-4.2.0-rc2
  checking whether the C++ compiler works... yes
  checking for C++ compiler default output file name... a.out
  checking for suffix of executables... 
  checking whether we are cross compiling... no
  checking for suffix of object files... o
  checking whether we are using the GNU C++ compiler... yes
  checking whether clang++ -std=gnu++11 accepts -g... yes
  checking for clang++ -std=gnu++11 option to enable C++11 features... unsupported
  
  pkg: error running the configure script for image.
  error: called from
      install at line 200 column 5
      pkg at line 392 column 9
  </code></pre>
  
  <p>But I think I installed GCC correctly:</p>
  
  <pre><code>gcc -v
  </code></pre>
  
  <p>Has the following output:</p>
  
  <pre><code>Es werden eingebaute Spezifikationen verwendet.
  COLLECT_GCC=gcc
  COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-apple-darwin15.6.0/6.2.0/lto-wrapper
  Ziel: x86_64-apple-darwin15.6.0
  Konfiguriert mit: ../gcc-6.2.0/configure --enable-languages=c++,fortran --with-gmp=/usr/local
  Thread-Modell: posix
  gcc-Version 6.2.0 (GCC) 
  </code></pre>
  
  <p>What is my mistake? Or what have i done wrong?</p>
  
  <hr>
  
  <p>[1] <a href="http://wiki.octave.org/Octave_for_MacOS_X#Homebrew" rel="nofollow">http://wiki.octave.org/Octave_for_MacOS_X#Homebrew</a></p>
  
  <p>[2] <a href="http://octave.sourceforge.net/image/index.html" rel="nofollow">http://octave.sourceforge.net/image/index.html</a></p>
  
  <p>[0] Macbook Specifications:
  MacBook Pro (13-inch, Mid 2012)</p>
  
  <p>2,5 GHz Intel Core i5</p>
  
  <p>16 GB 1600 MHz DDR3</p>
  
  <p>macOS Sierra (Version 10.12)</p>