Configuring ${DOCUMENTS} variable in Flash (Flex) Builder

When adding library reference in FB, if the particular .swc file is within the workspace, the FB will use ${DOCUMENTS} variable to refer to the targeted .swc file.

I had a problem when I created a maintenance branch in my SVN, being lazy to check out from the branch and re-setup my projects, I copied over my current working copy of trunk and do a quick switch. Every things work well except the ${DOCUMENT} variable is still referring to the old workspace directory.

Fortunately, I soon read from here that the ${DOCUMENTS} variable is actually set in the Workspace Preferences:-

Window -> Preferences -> General -> Workspace -> Linked Resources

You can also configure your custom variable there.