Eclipse: Insufficient access privileges to apply this update.

I use Eclipse for all my Java development (and Mac OS X for all my development). Today, a bug with portlet deployment to Liferay required me to update my Eclipse installation. For awhile, I’d seen (and ignored) an error when I ran Eclipse’s Check For Updates: the Eclipse IDE for Java EE Developers selection was grayed out with the message:

Insufficient access privileges to apply this update.

I assumed that the IT group here at work hadn’t given my user permissions on the /Applications/eclipse directory, and I’d never been motivated to investigate. Today, that motivation came. I quickly determined the fallacy of my assumption and, with nowhere else really to turn, I ran to Google. I found this:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=344977

It had this explanation:

In case anyone wants to workaround it manually, go to:

eclipse\p2\org.eclipse.equinox.p2.engine\profileRegistry\SDKProfile.profile

• Edit the most recent profile file
• Find the section in comment #1
• Remove the line:

  <property name='org.eclipse.equinox.p2.type.lock' value='1'/>

• Now start Eclipse and update it

I didn’t have that file, but I rooted around that directory and found a 0-byte file called .lock in this directory:

/Applications/eclipse/p2/org.eclipse.equinox.p2.engine/profileRegistry/epp.package.jee.profile

I don’t know where that file came from, but since it looked suspicious (and I was reasonably confident I could recreate the file with its original contents if it weren’t the culprit), I deleted that file, restarted Eclipse, and now my update works.