Originating a contract fails with 'unexpected_lazy_storage' ONLY when exception optimisation level is set to 'full-debug'

Question

I have a contract that originates correctly when exception_optimization_level is set to debug-message and default-line. The contract tests, compiles, and works as expected except for a bug that is only present on testnet.

I've used the full-debug level in the past to see more information, but now when I change the exception level I receive the following when trying to originate:

{
  errors: [
    {
      kind: 'permanent',
      id: 'proto.011-PtHangz2.michelson_v1.ill_typed_contract',
      ill_typed_code: [Array],
      type_map: []
    },
    {
      kind: 'permanent',
      id: 'proto.011-PtHangz2.michelson_v1.unexpected_lazy_storage',
      loc: 469
    }
  ],
  id: 'proto.011-PtHangz2.michelson_v1.unexpected_lazy_storage',
  kind: 'permanent'
}

According to the documentation unexpected_lazy_storage means:

a big_map or sapling_state type was found in a position where it could end up stored inside a big_map

Why do I only receive this error during origination when the exception level is set to full-debug and how do I fix it?

Answer 1

Full debug implies that exceptions are filled with as much information as possible. As you’ve seen, you must have a big map somewhere it shouldn’t be. I’m not sure if something changed or not in Michelson. It would be interesting to see where exactly at the location of the error. The Tezos client gives more information (also when typing).