Weird behavior of the "project_classpath" Eclipse launcher variable

In the context of a an Eclipse workspace containing a bunch of related Eclipse projects that were created by Buildship, the value of the “project_classpath” launcher variable seems resolve to a string with a mix of absolute filesystem pathnames (e.g., “/user/mishkin/myproject/bin/main”) and Eclipse workspace pathnames (e.g., “/myproject/bin/default”). FWIW I don’t see this behavior, at least in simple cases, in the context of projects that I created in Eclipse by hand (i.e., not using Buildship) which leads me to believe that the weirdness is somehow Buildship-related. Any ideas? Thanks.