tests: fix flaky reckless tests by waiting for the canned github server#9306
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Looks good to me! pyln.testing.utils.wait_for() already implements this poll-with-backoff pattern elsewhere in the suite - so could reuse it here instead of a hand-rolled loop?(though the custom loop works fine as-is!!)
| # first reckless invocation doesn't race it and get connection refused. | ||
| start = time.time() | ||
| while True: | ||
| assert server.poll() is None, "canned github server died" |
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The canned_github_server fixture Popens a Flask server and never waits for it to start listening; the git repository setup between the Popen and the yield usually gives it enough time. Under CI load it can lose that race: a valgrind-shard failure shows test_search's first reckless invocation getting connection refused within a second of the test starting, while Flask's "Running on http://127.0.0.1:..." banner only appears in the log after the test had already failed. Wait for the port to accept connections before yielding, and fail loudly if the server process dies instead of coming up. Changelog-None
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Observed on a CI run for #9286 (Valgrind Test CLN 1/12, test_search):
https://github.com/ElementsProject/lightning/actions/runs/29122024616/job/86461830290
The canned_github_server fixture starts a Flask server with Popen and
never waits for it to listen; the git repository setup between the
Popen and the yield usually gives it enough time. Under CI load it
can lose that race: in the failure above, test_search's first
reckless invocation got connection refused within a second of the
test starting, and Flask's "Running on http://127.0.0.1:39495"
banner only appears in the log after the test had already failed
(so the server did come up and bind its port -- just too late).
The fix waits for the port to accept connections before yielding, and
fails loudly if the server process dies instead of coming up.
Changelog-None