meshtastic_firmware/.github/prompts/mcp-repro.prompt.md

mode, description

mode	description
agent	Re-run a specific test N times to triage flakes; diff firmware logs between passes and failures (Copilot equivalent of the Claude Code /repro slash command)

/mcp-repro - flakiness triage for one test

Equivalent of .claude/commands/repro.md. Use when the operator says "that one test is flaky - dig in", "repro the direct_with_ack failure", "why does X sometimes fail?".

What to do

1. Parse the operator's input into two pieces:

   • Test identifier - either a pytest node id (has :: or starts with tests/) or a -k-style filter (plain substring like direct_with_ack).
   • Count - integer, default 5, cap at 20. If the operator asks for 50, negotiate down and explain (airtime + USB wear).

2. Sanity-check the hub via the list_devices MCP tool. If the test name references nrf52 or esp32s3 and the matching VID isn't present, stop and report - re-running won't help.

3. Loop N times. Each iteration:

   ./mcp-server/run-tests.sh <test-id> --tb=short -p no:cacheprovider
   

   -p no:cacheprovider keeps pytest from caching anything between iterations. Capture: exit code, duration, and (on failure) the Meshtastic debug firmware-log section from mcp-server/tests/report.html.

4. Tally results as you go:

   attempt 1: PASS (42s)
   attempt 2: FAIL (128s)    ← fw log captured
   attempt 3: PASS (39s)
   attempt 4: FAIL (121s)
   attempt 5: PASS (41s)
   --------------------------------------------------
   pass rate: 3/5 (60%)  |  mean duration: 74s
   

5. On mixed outcomes, diff the firmware logs between one representative pass and one representative fail. Focus on:

   • Error-level lines present only in failures (PKI_UNKNOWN_PUBKEY, Alloc an err=, Skip send, No suitable channel, NAK)
   • Timing around the assertion point (broadcast sent? ACK received? retry fired?)
   • Device-state fields that changed between attempts

   Surface the top 3 differences as a compact "passes when / fails when" table with uptime timestamps. Don't dump full logs.

6. Classify the flake into one of:

   • LoRa airtime collision - pass rate improves with fewer concurrent transmitters. Suggest a time.sleep gap or retry bump in the test body.
   • PKI key staleness - first attempt fails, subsequent ones pass; existing retry-loop pattern in test_direct_with_ack.py is the fix.
   • NodeInfo cooldown - Skip send NodeInfo since we sent it <600s ago in fail-only logs; needs a broadcast_nodeinfo_ping() warmup.
   • Hardware-specific - one direction consistently fails, firmware versions differ, CP2102 driver wedged, etc. For a device wedged past touch_1200bps, recommend uhubctl_cycle(role=..., confirm=True) to hard-power-cycle its hub port (requires uhubctl installed).
   • Device went dark mid-run - fails from some iteration onward and never recovers; firmware log stops arriving. Almost always a Guru crash with frozen CDC. Recommend uhubctl_cycle before the next iteration; escalate to replug if that also fails.
   • Unknown - say so. Don't invent a root cause.

7. Report back with:

   • Pass rate + mean duration.
   • Classification + the specific log evidence for it.
   • A concrete next step (tighter assertion, more retries, open /mcp-diagnose, file a bug, nothing).

Examples

• tests/mesh/test_direct_with_ack.py::test_direct_with_ack_roundtrip[esp32s3->nrf52] 10 - 10 runs of that parametrized case.
• broadcast_delivers - no ::, no tests/; treat as -k broadcast_delivers; runs every match 5 times.
• tests/telemetry/test_device_telemetry_broadcast.py 3 - shorter count for a slow test.

Notes

• If the FIRST attempt fails and the rest pass, that's a state-leak signature - suggest starting from --force-bake or a clean device state rather than chasing the first-failure firmware logs.
• If ALL N fail, this isn't a flake - it's a regression. Say so, stop iterating, escalate to /mcp-test for full-suite context.
• Don't rebuild firmware during triage. Flakes that only reproduce under different firmware belong in a separate session with a plan.