Cache file could not be renamed error

Problem

I installed a fresh copy of Eclipse. I opened its Update Software section to install some software. The Mars section took forever to load and in the end threw this error:

Unable to read repository at http://download.eclipse.org/releases/mars.
An error occurred while downloading http://download.eclipse.org/releases/mars/201506241002/content.xml.xz.
The cache file /home/joe/eclipse/p2/org.eclipse.equinox.p2.repository/cache/downloading/467561694 could not be renamed to /home/joe/eclipse_/p2/org.eclipse.equinox.p2.repository/cache/467561694.

Solution

This error persisted no matter if I restarted Eclipse. In the end, I just deleted the p2/org.eclipse.equinox.p2.repository/cache directory. The software list uploaded fine after that.

Tried with: Eclipse 4.5 and Ubuntu 14.04