Here’s a similar question from the eclipse.tools newsgroup and the corresponding reply from the Eclipse Team:
THE QUESTION:
I’m using Version: 2.1.0, Build id: 200302270800 on Windows 2000.
When I run an external tool (it happens to be a batch file) I see the
following dialog message:
“An error occurred attempting to expand the variable working_set. No working set specified.”
The external tool seems to run okay, despite the error message, but the message is a nuisance. I think I know what a “working set” is but I don’t understand why I should have to specify one in order to run the external tool.
REPLY FROM THE ECLIPSE TEAM
Check out the Refresh tab of the launch configuration you’re running. The error indicates that you somehow managed to tell the configuration to refresh a working set when it runs but you didn’t specify a particular working set. The config dialog shouldn’t allow you to do this, so it sounds like we’ve got a bug here.
The direct reference for the post is: http://dev.eclipse.org/newslists/news.eclipse.tools/msg60360.html
You might want to follow up on the Eclipse site for more information.
–Scott
MyEclipse Support