Portal upgrade fails during the PRECONFIG-WP-PTF-601 configuration task with 'Duplicate target' error

The IBM® WebSphere® Portal upgrade fails during the PRECONFIG-WP-PTF-601 task.

The ConfigTrace.log shows the following:
BUILD FAILED
Duplicate target: `configure-web-resource-servlet'

Total time: 2 seconds

This condition occurs because during the init portion of the task being executed, the code finds multiple occurrences of the sub-task listed in quotes (in this case, `configure-web-resource-servlet') in the various XML files it parses through.

It is unknown exactly how these duplicates originally occurred. Usually it is because a duplicate XML file exists, and therefore the sub-task is found in each file by the init phase. When multiple instances are found, the "Duplicate target" error is thrown.

To resolve this issue, you can use the following technique.

1) Search the <portal_root>/config directory for the text string (in this case, `configure-web-resource-servlet')

2) In this case this string was found twice: once in <portal_root>/config/includes and once in <portal_root>/config/actions, in a file by the same name of wrs_cfg.xml

-- If the XML files found are in the same directory, move (not delete) one of the files out of that location.

-- If the XML files are in different location, like this example, move (not delete) the file from the <portal_root>/config/includes directory.

3) After moving the duplicate file, re-attempt the Portal upgrade.