The runtime is a process singleton, so multi-node tests mean multiple
processes. tests/common/mod.rs is the reusable harness (precedent: RFC
019 c6 / tests/stack_diag.rs self-re-exec, extended to live tailing):
re-execs the current test binary as named roles, tails stdout/stderr on
reader threads, waits on protocol-visible lines with bounded timeouts
(panic dumps carry the full transcript), and Drop SIGKILLs+reaps so a
panicking test leaves no orphan or zombie. Children run with
--test-threads=1 --quiet --nocapture; the last flag is load-bearing —
libtest's capture would otherwise swallow role output.
Port assignment is race-free by construction: children bind port 0 and
announce the concrete address (LISTENING <addr>); the parent never
pre-picks.
Smoke suite per roadmap: two real nodes, handshake-less TCP connect
through the real framed codec (one Heartbeat across, clean close seen on
both sides, both exit 0), plus reap-on-drop proven via ESRCH and
nonzero-exit surfacing. Flake budget stated in the module doc: 10 s
bound per wait, 10/10 clean at authoring, >1/100 failures = regression.
