i copied items i cared about from this folder in a project that had working
debug configurations:

.metadata/.plugins/org.eclipse.debug.core/.launches

into the same folder in the new project.

with the things all being named the same, like GenesisII-trunk, the debug
configurations worked without needing to be re-created.  nice.

be careful though; if the new project has environment variables that are
different from the old project, and those variables are part of the
configuration, then they'll need to be modified.