Broken Fastlane installation / mix Ruby versions
<p>I'm quite new to ruby, gems and such but got fastlane installed and setup quite nicely. I then ran into this issue for deliver:</p>

<p><a href="https://github.com/fastlane/deliver/issues/349" rel="nofollow">https://github.com/fastlane/deliver/issues/349</a></p>

<p>I tried to update to the lastest version of fastlane but then ran into this issue:</p>

<p><a href="https://github.com/fastlane/fastlane/issues/567" rel="nofollow">https://github.com/fastlane/fastlane/issues/567</a></p>

<pre><code>ERROR: While executing gem ... (Errno::EPERM)
Operation not permitted - /usr/bin/sigh
</code></pre>

<p>I tried the</p>

<pre><code>gem update -n /usr/local/bin fastlane
gem update -n /usr/local/bin sigh
gem update -n /usr/local/bin deliver
</code></pre>

<p>without success. These only led me to this error:</p>

<pre><code>Unable to activate deliver-1.9.0, because plist-3.2.0 conflicts with plist (~&gt; 3.1.0 ...
</code></pre>

<p>I also tried</p>

<pre><code>sudo su
sudo gem install fastlane --verbose
exit
</code></pre>

<p>Without success. After that I tried to install bundler, a new ruby version and do cleanups and reinstalls. No success. Now everything seems to be in a bad state and trying to install fastlane with the normal command</p>

<pre><code>install fastlane --verbose
</code></pre>

<p>leads to</p>

<pre><code>You don't have write permissions for the /Library/Ruby/Gems/2.0.0 directory.
</code></pre>

<p>Same command with sudo gives:</p>

<pre><code>/usr/local/lib/ruby/gems/2.3.0/gems/snapshot-1.6.0/lib/snapshot/version.rb
ERROR: While executing gem ... (TypeError)
no implicit conversion of nil into String
</code></pre>

<p>What to do??</p>

<p><code>ruby -v</code> gives me <code>ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-darwin15]</code> and <code>echo $PATH</code> gives me <code>/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin</code></p>