Launch the Console application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ If you’re running Mac OS X 10.7 or later, open LaunchPad. Click Utilities, then Console in the page that opens.
Select "/var/log/install.log" from the file list. Post the messages from the last installation attempt, starting from the time when you launched the Installer or Software Update. Post the log text, please, not a screenshot.
If there are runs of runs of repeated messages, please post only one example of each. Don’t post many repetitions of the same message.
Not sure if you still have issues but I just had the same issue updating Safari. I tailed the install log and found that one script was not completing (tail -F /var/log/install.log). In this case it was a preinstall script named zzz_cleanUpgrade. Then run "ps ax | grep zzz_cleanUpgrade" to get the process id and kill it (i.e. "sudo kill 13349")