Deal duration too short: Lotus minExpiration requires >= 608,730 epochs

[snail8501]

Deal duration too short: Lotus minExpiration requires >= 608,730 epochs

Summary

When submitting deals using the Boost CLI, Lotus enforces a sector minimum expiration (minExpiration). If the submitted expiration is less than this minimum, Lotus will reject the transaction or force the expiration to the minimum value, which can cause the deal to fail or behave unexpectedly.

Observed code location:

• Affected client code: cmd/boost/deal_cmd.go (the duration flag default is 518400, equal to 180 days)
• Lotus's minimum expiration calculation (illustrative):

  minExpiration := sector.TicketEpoch + policy.MaxPreCommitRandomnessLookback + msd + policy.GetMinSectorExpiration()
  if expiration < minExpiration {
    expiration = minExpiration
  }

Under current chain and policy parameters, the difference between minExpiration and a typical expiration is approximately 608,730 epochs. Therefore the --duration value must be set to at least 608730 epochs, otherwise the proposal may be rejected.

Reproduction Steps

1. Submit a deal using the Boost CLI (online or offline) without explicitly setting --duration, or set --duration to a value less than 608730 (for example, the default 518400).
2. Lotus will reject the proposal or raise an error during processing because expiration < minExpiration.

Actual Behavior

• The proposal may appear to be sent successfully from the client, but Lotus will reject it during on-chain validation or force the expiration to a larger value, resulting in an unexpected deal state.

Expected Behavior

• The Boost CLI should validate the duration locally and show a clear error if it is too short, or the default should be set to a safe value (>= 608,730 epochs) to avoid on-chain failures.

Suggested Fixes

1. Add a runtime validation for duration at the start of dealCmdAction in cmd/boost/deal_cmd.go:

const minDuration = 608730
if cctx.Int("duration") < minDuration {
  return fmt.Errorf("duration too short: Lotus requires at least %d epochs (≈ %.1f days). Please set --duration >= %d", minDuration, float64(minDuration)/2880.0, minDuration)
}

2. Optionally, change the default duration in dealFlags from 518400 to 608730 (or a more conservative value) while keeping the runtime check to handle future chain parameter changes:

@@
   &cli.IntFlag{
     Name:  "duration",
     Usage: "duration of the deal in epochs",
-        Value: 518400, // default is 2880 * 180 == 180 days
-    },
-+    &cli.IntFlag{
-+        Name:  "duration",
-+        Usage: "duration of the deal in epochs",
-+        Value: 608730, // default adjusted to meet Lotus minExpiration
-+    },
    Value: 608730, // default adjusted to meet Lotus minExpiration
  },

3. Add documentation to the README noting that --duration is specified in epochs and must meet the chain minimum expiration requirement (currently approximately 608,730 epochs).

Impact

• The deal and offline-deal commands in the Boost CLI. Users who do not explicitly set a sufficiently large --duration are affected.

Logs / Error Examples

• The exact Lotus rejection message may vary by version; common symptoms include deal proposals being rejected or failing validation during chain inclusion.

Notes

• 608,730 epochs is approximately 608730 / 2880 ≈ 211.3 days when using 2880 epochs per day, but the authoritative unit is epochs.

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