paludis -ip world
Building target list...
Building dependency list...
Unhandled exception:
  * In program paludis -ip world:
  * When performing install action from command line:
  * When executing install task:
  * When adding PackageDepSpec 'virtual/baselayout':
  * When loading VDB PROVIDEs map using '/var/db/pkg/.cache/provides':
  * When parsing dependency string '':
  * When handling lexer token '' (1):
  * When parsing package dep spec '' with parse mode 'permissive':
  * When splitting out category and package names from '':
  * Name '' is not a valid qualified package name (paludis::QualifiedPackageName Error)