Cosmos-sdk: block.TimeIotaMs is 0 on exported genesis

[michaelfig]

Summary of Bug

After exporting and reinitialising the chain the consensus_params.block.time_iota_ms value is 0. This fails when restarting the chain with the new genesis.json.

Version

v0.34.4-0.20200511222341-80be50319ca5

Steps to Reproduce

1. gaiad export --for-zero-height > newgenesis.json
2. gaiad unsafe-reset-all
3. cp newgenesis.json ~/.gaiad/config/genesis.json
4. gaiad start

Fails with:

block.TimeIotaMs must be greater than 0. Got 0.

---

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[alexanderbez]

Yes, this is because we're not saving/exporting Block.TimeIotaMs -- I intentionally didn't include this because this value really isn't meant to change. I guess we have no choice but to include it.

@jgimeno do you think you have the bandwidth to take this on? It should be pretty straight forward.

[jgimeno]

Ok, I think we have two options here.

1. When exporting search for this value in the genesis file (maybe a little bit ugly just for one value?) or 2. provide this value in the abci.ConsensusParams from tendermint that is included in abci.RequestInitChain (but I saw a comment that this specific field is not shared with the application).

@aaronc , @alexanderbez , @alessio opinions?

[alexanderbez]

@jgimeno it's a one-line fix:

diff --git a/server/export.go b/server/export.go
index 672432ad0..ff3f9be5f 100644
--- a/server/export.go
+++ b/server/export.go
@@ -75,8 +75,9 @@ func ExportCmd(ctx *Context, cdc codec.JSONMarshaler, appExporter AppExporter) *
                        doc.Validators = validators
                        doc.ConsensusParams = &tmtypes.ConsensusParams{
                                Block: tmtypes.BlockParams{
-                                       MaxBytes: cp.Block.MaxBytes,
-                                       MaxGas:   cp.Block.MaxGas,
+                                       MaxBytes:   cp.Block.MaxBytes,
+                                       MaxGas:     cp.Block.MaxGas,
+                                       TimeIotaMs: doc.ConsensusParams.Block.TimeIotaMs,
                                },
                                Evidence: tmtypes.EvidenceParams{
                                        MaxAgeNumBlocks: cp.Evidence.MaxAgeNumBlocks,

[jgimeno]

Oh yes, the doc was there :D

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[michaelfig]

Marked as done and merged. I'm closing.