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Debugging

Logging in Aztec.nr​

On this section you can learn how to debug your Aztec.nr smart contracts and common errors that you may run into.

You can log statements from Aztec.nr contracts that will show ups in the Sandbox.

info

The Noir standard library std::println function will not work in Aztec contracts. You must use the debug_log and debug_log_format defined below.

Import debug_log​

Import the debug_log dependency from Aztec oracles:

use dep::aztec::oracle::debug_log::{ debug_log };

Write log​

Write debug_log() in the appropriate place in your contract.

debug_log("here");

Other methods for logging include:

debug_log_format(): for logging Field values along arbitrary strings.

debug_log_format("get_2(slot:{0}) =>\n\t0:{1}\n\t1:{2}", [storage_slot, note0_hash, note1_hash]);

debug_log_field(): for logging Fields.

debug_log_field(my_field);

debug_log_array(): for logging array types.

debug_log_array(my_array);

Start Sandbox in debug mode​

Update the DEBUG environment variable in docker-compose.sandbox.yml to the following:

# ~/.aztec/docker-compose.sandbox.yml

# ...

aztec:
  image: "aztecprotocol/aztec"
  ports:
    - "${PXE_PORT:-8080}:${PXE_PORT:-8080}"
  environment:
    DEBUG: aztec:simulator:client_execution_context, aztec:sandbox, aztec:avm_simulator:debug_log
    LOG_LEVEL: verbose # optionally add this for more logs
  # ...

and start the sandbox normally.