--setting-sources is a command-line option that chooses which settings files Claude Code loads. New helper code takes the setting sources in use and writes them back out as a --setting-sources= argument. If a source is not valid, the error now lists the valid options, starting "Invalid setting source:".
Why
The setting sources you chose can be passed along to other Claude Code processes, and a mistyped source now tells you what is accepted.
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtThe finding does not confirm that the rebuilt argument is passed to child processes, only that this appears to be its purpose.
Anthropic's release notes agreeFixed --setting-sources (and SDK settingSources) not being forwarded to spawned sessions: teammates, /bg, claude agents sessions and…
