Re-investigation of `kixelated/moq` commit 45db108 ("moq-lite/moq-relay:
hop-based clustering") revealed that Lite-04 IS wire-incompatible with
our Lite-03 codec on Announce / AnnounceInterest / Probe — contradicting
the earlier reasoning that motivated 4b73626. Specifically:
- Announce.hops: Lite-03 writes a single varint count of hops; Lite-04
writes count + count × varint Origin ids. (`rs/moq-lite/src/lite/
announce.rs:67-73` branches on Version explicitly.)
- AnnounceInterest: Lite-04 added an `exclude_hop` varint after the
prefix.
- Probe: Lite-04 added an `rtt` varint after `bitrate`.
Subscribe / SubscribeOk / SubscribeDrop / Group / GroupHeader framing is
unchanged across Lite-03↔Lite-04 — but the Announce/Probe drift alone is
enough to desync a Lite-04-preferring relay if it picks `moq-lite-04`
from our advertised list. We'd encode Announce hops as a bare varint
where the peer expects `len + len × u62`, and the connection aborts on
the first Announce exchange.
Pin `wt-available-protocols` back to `["moq-lite-03"]` until
`MoqLiteCodec` gains version-aware Announce / AnnounceInterest / Probe
codecs and `MoqLiteAnnounce.hops` becomes a list rather than a single
varint. Reverting 4b73626 — the LITE_04 constant stays in MoqLiteAlpn
for documentation, but is no longer plumbed into the factory's
sub-protocol list.
Reverts the wire-format expansion in 4b73626. The factory and ALPN
kdocs are rewritten to spell out the codec diff so the next person who
considers re-enabling Lite-04 reads the actual blocker first.
https://claude.ai/code/session_014JfZJHSTvyYYWJbC9VbB47
Claude
ea90685a86