git-annex initremote --sameas=foo --private is not actually
private, or not in a way that seems to make sense.
Currently, it writes to the git-annex branch, adding in remote.log the config uuid of the sameas remote.
It should be possible to avoid writing that there. Since the config uuid is the only place a sameas remote touches the git-annex branch, this would allow making up sameas remotes for local use.
But also, and worse, that actually makes location log changes for remote foo be logged to the private journal. That happens because remote.name.annex-private is set for the sameas remote, and it has the same annex-uuid as foo. This is highly surprising and wrong behavior!
The fix will be to make remote.name.annex-private affect the annex-config-uuid when there is one, rather than the annex-uuid.