Jenkins "Failed to create a temporary file in /" Why is it trying to write a file there?
<p>Yesterday <code>Jenkins</code> was great. Today all builds fail.</p>

<pre><code>Jenkins Version 1.650
All plugins up to date.
Latest CentOS. Fully patched.
Jenkins installed via yum. 
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<p>When trying to get console output of the job I just ran, the web console states there is no log: </p>

<pre><code>No such file: /1/log
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<p>When I look at <code>/var/log/jenkins.log</code>: </p>

<pre><code>Feb 24, 2016 9:06:16 PM jenkins.model.PeepholePermalink updateCache
WARNING: Failed to update hudson.model.FreeStyleProject@24ab29e4[rails-server] lastFailedBuild permalink for null
java.io.IOException: Failed to create a temporary file in /
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<p>So looking at this log I'm wondering, why is Jenkins trying to write anything to <code>/?</code> Is that the literal <code>/</code>, not a relative path? Sure looks like it. That's not OK, so how do I fix it? </p>

<pre><code>Environment vars: 

Name  ↓   Value   
_   /etc/alternatives/java
HOME    /var/lib/jenkins
LANG    en_US.UTF-8
LOGNAME jenkins
NLSPATH /usr/dt/lib/nls/msg/%L/%N.cat
PATH    /sbin:/usr/sbin:/bin:/usr/bin
PWD /
SHELL   /bin/bash
SHLVL   3
TERM    xterm-256color
USER    jenkins
XFILESEARCHPATH /usr/dt/app-defaults/%L/Dt
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<p>Permissions on /var/lib/jenkins are correct. <code>/tmp</code> is writeable and the jvm is using <code>/tmp</code> for <code>java.io.tmpdir</code>   </p>

<p>I gave Jenkins permissions to write to <code>/</code> to see what would happen when a build occurs. It wrote the following files: </p>

<pre><code>lrwxrwxrwx   1 jenkins jenkins    2 Feb 24 21:47 lastFailedBuild -&gt; 10
lrwxrwxrwx   1 jenkins jenkins    2 Feb 24 21:47 lastUnsuccessfulBuild -&gt; 10
drwxr-xr-x   2 jenkins jenkins    4.0K Feb 24 21:47 10
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