Common functionality for Debian and RPM buildpackage scripts
| Variable | index_name | Undocumented |
| Variable | wc_name | Undocumented |
| Function | dump_tree | dump a tree to output_dir |
| Function | wc_index | Get path of the temporary index file used for exporting working copy |
| Function | write_wc | write out the current working copy as a treeish object |
| Function | drop_index | drop our custom index |