xversion: epoch identity pins refuse any post-M18 'old' side
open by a73x
test/xversion.sh pins its old side by absence of pre-M18 signals (no 'sessions=' in stats, no term_modes/term_title/term_event arms), so running it with old=v0.0.1-10 fails 5 identity probes by construction while all 5 real compat legs pass. For release gating, 'old = last release' is the pairing that matters. Options: make the epoch probes conditional on a declared XVER_OLD_EPOCH, or re-pin to feature-detect per leg. Also: the harness has no leg for a NEW client's prefix chord against a pre-0x0c daemon (expiry banner '[no session list: upgrade muxd]') — verified by hand 2026-08-19, worth codifying.
Comments
a73x
2026-08-29: still pinned on 'sessions=' presence/absence (test/xversion.sh:322-324); the rig only runs against ../mux-xver-old at v0.0.1-5.