Nested call trace

Why use this example

Use this pattern to reproduce a failure or follow an execution from Solidity source into calls and EVM opcodes. The entry isolates nested call trace so its input, result, and state changes stay easy to compare.

Solidity to run

contract Child { function ping() external pure returns (uint256) { return 42; } }
contract Parent {
  Child child = new Child();
  function run() external view returns (uint256) { return child.ping(); }
}
Parent parent = new Parent()
parent.run()

What to expect

Parent.run() returns 42 and the Calls view records the nested external call to Child.ping().

Continue the investigation

Change a value, add another expression, or open Inspect after the run. Accepted entries remain available to the next entry, and the clean replay keeps the complete result reproducible.