Comment 6 for bug 275912

Prodoc,
Just to note, As I understand all (if no most) of the eclipse preferences (not only bzr-eclipse) are tied to the workspace, actually if you use the File -> Switch Workspace action, it 'll allow you to copy your preferences and setting to the newly created workspace.

I agree that this is a "power-user" feature.
I don't have an opinion on which is the way to go.
Also, just to help you workaround your current issue, in the meantime this is fixed, you could modifiy the absolute path to a relative in the preferences files stored in the .metadata folder of your workspace.
there are two files that need to be modified in order to this hack/workaround to actually work:
1) <wokrspace>/.metadata/.plugins/org.eclipse.core.runtime/.settings/org.vcs.bazaar.eclipse.core.prefs
2) <wokrspace>/.metadata/.plugins/org.eclipse.core.runtime/.settings/org.vcs.bazaar.eclipse.ui.prefs

both files have similar content, you could modify the EXECUTABLE value of both and make it relative to the wokrspace.

I didn't test this workaround, but I think it *should* work

Cheers,