title: idn2.h: No such file or directory
body: <p>I am on 64-bit Centos 6.6 and want to install libidn2-devel. I tried <code>yum install libidn2-devel</code> and that didn't work. I tried downloading rpms from various websites from Internet(resolving recursive dependencies manually!)</p>
  
  <p>(Not so) Soon I stuck at the one of the dependencies</p>
  
  <pre><code>libidn2.so.0()(64bit) is needed by libidn2-devel-0.10-1.sdl7.x86_64
  </code></pre>
  
  <p>which I could not find anywhere on the Internet (for CentOS).</p>
  
  <p>Eventually, I downloaded the <a href="https://gitlab.com/libidn/libidn2" rel="nofollow noreferrer">source</a> and tried to build it.</p>
  
  <pre><code>wget -c ftp://alpha.gnu.org/gnu/libidn/libidn2-0.10.tar.gz
  tar -xvzf libidn2-0.10.tar.gz
  ./configure
  make
  </code></pre>
  
  <p>Success!</p>
  
  <p>However, when I used it to run a module, it gives me </p>
  
  <pre><code>error: idn2.h: No such file or directory
  &lt;idn2_variable&gt; was not declared in this scope
  </code></pre>
  
  <hr>
  
  <p>PS : RPM seems weird</p>
  
  <pre><code>$ rpm -q libidn2-devel
  package libidn2-devel is not installed
  $ rpm -q libidn2
  libidn2-2.0.4-1.el6.x86_64
  </code></pre>