The visible-ASCII session-id check sends a raw initialize POST outside the
SDK transport, because the transport does not expose the MCP-Session-Id
response header. That fetch carried no abort signal and its body was never
read or cancelled.
A server that accepts the connection and never responds hung the scenario
here, before teardown, so the DELETE bound added in #316 never came into
play. And since the probe's `Accept` includes `text/event-stream`, a server
answering with an open SSE stream left the body unconsumed and leaked the
connection for the rest of the run.
Bounding the probe at 5s matches the existing session-termination bound.
#427 is the structural fix for the hang class; this is still worth having
for fast failure and for attributing the failure to this check rather than
to whatever the runner-level timeout happens to interrupt.
Fixes#428
Co-authored-by: Avi Seth <aviseth@users.noreply.github.com>
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