git clone [email protected]:sam-goldman/sender-bug.git

cd sender-bug && forge install

The following command logs the correct contract address, 0x5FbDB2315678afecb367f032d93F642f64180aa3:

forge script script/Counter.s.sol

You can verify that this is the expected address by running:

cast compute-address 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 --nonce 0

Adding --sender to the command above results in a contract address of 0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512, which is incorrect.

forge script script/Counter.s.sol --sender 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266

Notice that the --sender is the same address that's broadcasting the deployment, so the deployed contract's address shouldn't change.

The logged contract address is calculated using a sender nonce of 1, which you can verify with the command:

cast compute-address 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 --nonce 1

Adding --sender to the original command and using vm.prank instead of vm.broadcast results in a contract address of 0x9fE46736679d2D9a65F0992F2272dE9f3c7fa6e0, which is also not correct, and is different from the address created by vm.broadcast above.

Run Counter2.s.sol, which is the same as the previous script, except it uses vm.prank:

forge script script/Counter2.s.sol --sender 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266

The logged contract address is calculated using a sender nonce of 2, which you can verify with the command:

cast compute-address 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 --nonce 2