After upgrading to Berkeley DB 4.3 and later, I'm seeing repository errors and svnadmin recover fails.

Prior to Berkeley DB 4.3, svnadmin recover worked to upgrade a Berkeley DB repository in-place. However, due to a change in the behavior of Berkeley DB in version 4.3, this now fails. Use this procedure to upgrade your repository in-place to Berkeley DB 4.3 or later:

• Make sure no process is accessing the repository (stop Apache, svnserve, restrict access via file://, svnlook, svnadmin, etc.)
• Using an older svnadmin binary (that is, linked to an older Berkeley DB):
  1. Recover the repository: svnadmin recover /path/to/repository.
  2. Make a backup of the repository.
  3. Delete all unused log files. You can see them by running svnadmin list-unused-dblogs /path/to/repository
  4. Delete the shared-memory files. These are files in the repository's db/ directory, of the form db.00*

The repository is now usable by Berkeley DB 4.3.