Renaming a category requires to touch every PR in that category, because each report contains the name of its category.
To rename category
B, proceed as follows:
A, changing its category to
B. This can be done with any gnats client; check the archives of the help-gnats mailing list for hints about automating this step.
gen-index(see Regenerating the index (Keeping Track)) to refresh the index file.
A. When a follow-up to an existing PR arrives via e-mail, gnats 4.x checks that both the category and the PR number indicated in the mail exist (this is a sanity check).
To reduce the risk of new reports being filed to category
A, change its description in the categories file to
something like obsolete, use category