The crater subdirectory is where badly broken modules go until the complete
removal can be done. The reasons to move a module there can include:
  - The source archive is nowhere to be found on the internet;
  - The source code doesn't compile anymore or is broken due to deprecations
    and there's no maintenance done upstream;
  - The module has been replaced by a new one.

Complete removal will be made once no problems have been reported for a good
while and that most modules have been tested to work well without it.
