After upgrading to the latest version of Tezos, I received an error when running the baker: "Assert_failure vendors/irmin-pack/IO.ml:104:6". The node, endorser, accuser seem to run just fine.

Any idea what I have to do?


  • Can you give a complete log from your baker ? On which commit hash are you ? How do you run your baker ?
    – vect0r
    Jan 3, 2020 at 13:12
  • Hey vect0r - thanks for the answer. That's about the full log. In the meantime, I have downloaded and loaded the latest snapshot from tezosshots.com but it mentions ./tezos-node run tezos-node: Error: Invalid data directory version '0.0.4' (expected '0.0.3'). Any idea how to solve that? Jan 3, 2020 at 14:28
  • My bad - I was running the my old server again (mistake in custom script). It seems to be loading now. So the above error had to do with the upgrade of Irmin since the October release (tezos.gitlab.io/releases/october-2019.html). Reimporting a snapshot did the trick... Jan 3, 2020 at 14:39
  • 1
    Yes. As it is a new storage backend, you need to "upgrade" your storage. The easiest way to get it is, indeed, importing a snapshot. So the baker fails directly, without other logs, ok. Is working now ? With the last storage and an up to date node/baker/… ?
    – vect0r
    Jan 3, 2020 at 14:47
  • Yes you're right. Everything works fine now after recompiling and reimporting a snapshot. Thanks! Jan 9, 2020 at 15:35

1 Answer 1


Solved by ensuring that the storage was upgraded an in accordance with the Tezos binaries (See op comments).

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