Policies to retire functionality

Draft of thorn and parameter retirement policies

At release time, the main Einstein Toolkit thornlist in the manifest [1] should only contain thorns that are supported and actively maintained. Thorns that do not meet these requirements are candidates for retirements.

In order to retire a thorn or parameter:

• it needs to be marked as deprecated for at least one release. Deprecation notices appear in the release announcement.
  • for parameters we would like a means to mark them as deprecated in param.ccl (not implemented yet)
  • thorns are to be marked as deprecated in the thornlist
• deprecated thorns are to be listed on the ET website
• In order for a thorn to be retired, no other active thorn's testsuite may depend on it, unless the test is designed to only test the to-be-retired thorn.
• Deprecating and finally retiring a thorn both needs to be result of a public discussion, usually on one of the public meetings (phone calls).