Xcode Installation Alert: “Please Close iTunes” — Fix

While installing Xcode on Mac OS X 10.6.8, I ran into this problem: almost at the very end of the installation, a warning pops up

Installation Alert — In order to continue installation, please close the following application: iTunes

The funny thing is that iTunes isn’t running.

OK, click the magnifying glass button — iTunes launches, quit it, but the window keeps hanging there, won’t close, and the installation doesn’t continue. Stuck…

The fix

It isn’t iTunes itself that’s in the way, but its background helper, iTunesHelper, which starts with the system. You need to close it.

Open Terminal (Applications → Utilities) and run:

killall iTunesHelper

If the system says you don’t have permission, run it with sudo and enter the administrator password.

You can also do it without Terminal: open Activity Monitor, find the iTunesHelper process in the list and quit it.

After that, the Installation Alert window closes and the Xcode installation continues.