What
Compaction is when Claude Code summarizes a long conversation to free up room. Claude Code can fall back to a backup model when the one it asked for is not available. During compaction, a signal that such a switch happened is now raised as an error. When an error is caught, Claude Code can, under some conditions, put the current model back into its list of backup models. Before, compaction handled only requests to fall back.
Why
This may change how well compaction copes when the model switches to a backup.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
It is not clear what condition decides whether the current model is put back into the backup list.