nspcc-dev
question: how to get panic message?
I deployed your divisible NFT to the testnet. When I tried minting I initially made the mistake of not providing data in the transfer. Which caused an abort I assumed here
https://github.com/nspcc-dev/neo-go/blob/3dbd36ef70c902ace1552b849a00a454a3fad73b/examples/nft-d/nft.go#L367-L369
The actual exception message was:
"exception": "at instruction 29 (SYSCALL): failed native call: at instruction 1861 (ABORT): ABORT",
I noticed this snippet slightly up in the code https://github.com/nspcc-dev/neo-go/blob/3dbd36ef70c902ace1552b849a00a454a3fad73b/examples/nft-d/nft.go#L354-L359
which I assumed would print the reason, but the logs don't show this. My question is; how do I get the panic message?
To reproduce
curl --location --request POST 'http://rpc1.t5.n3.nspcc.ru:21332/' \
--header 'Content-Type: text/plain' \
--data-raw '{
"jsonrpc": "2.0",
"id": 1,
"method": "invokescript",
"params": ["CwIAypo7DBSnXW9dVbO8uPNzxHuKeWjqtp/ryAwUSlJutU7JooD+W5Gsslkavh9RHzcUwB8MCHRyYW5zZmVyDBTPduKL0AYsSkeO41VhARMZ88+k0kFifVtS",[{"account":"0x371f511fbe1a59b2ac915bfe80a2c94eb56e524a","scopes":"CalledByEntry"}]]
}'
how do I get the panic message?
Currently, the design of the contract doesn't allow the external user to get the panic message. As you noticed, the code snippet that handles panic message just logs it: https://github.com/nspcc-dev/neo-go/blob/3dbd36ef70c902ace1552b849a00a454a3fad73b/examples/nft-d/nft.go#L354-L359
The log message will be displayed inside the running node logs, so accessing the logs is the only way to get the logged panic message. ABORT doesn't have the ability to provide some message error with it. At the same time we can't replace util.Abort() with panic(message) because, according to the standard:
If the receiver doesn't want to receive this transfer it MUST abort the execution.
Log messages are not saved, they're only visible in the node logs:
Sep 27 08:55:17 kaede neogo-testnet-rpc[417627]: 2022-09-27T08:55:17.183Z INFO runtime log {"tx": "4d3b13fb5435e3f4cb1540aee14fec9f664a5b6a1a7f2af20e2afc93cd8016d9", "script": "c8eb9fb6ea68798a7bc473f3b8bcb3555d6f5da7", "msg": "invalid 'data'"}
Sep 27 08:55:17 kaede neogo-testnet-rpc[417627]: 2022-09-27T08:55:17.183Z WARN contract invocation failed {"tx": "4d3b13fb5435e3f4cb1540aee14fec9f664a5b6a1a7f2af20e2afc93cd8016d9", "block": 797668, "error": "at instruction 29 (SYSCALL): failed native call: at instruction 1861 (ABORT): ABORT"}
ah I see. I thought runtime.log was writing elsewhere (didn't look at the implementation). Feels like we kind of need opcode.ABORT_WITH_REASON, no?
runtime.log
It's a regular System.Runtime.Log syscall.
opcode.ABORT_WITH_REASON
We have the same issue with ASSERT, related to neo-project/neo#2782. Maybe if we just save/return log messages it'd be OK (even though it'll not solve neo-project/neo#2782 completely).
Log messages are not saved, they're only visible in the node logs:
Sep 27 08:55:17 kaede neogo-testnet-rpc[417627]: 2022-09-27T08:55:17.183Z INFO runtime log {"tx": "4d3b13fb5435e3f4cb1540aee14fec9f664a5b6a1a7f2af20e2afc93cd8016d9", "script": "c8eb9fb6ea68798a7bc473f3b8bcb3555d6f5da7", "msg": "invalid 'data'"} Sep 27 08:55:17 kaede neogo-testnet-rpc[417627]: 2022-09-27T08:55:17.183Z WARN contract invocation failed {"tx": "4d3b13fb5435e3f4cb1540aee14fec9f664a5b6a1a7f2af20e2afc93cd8016d9", "block": 797668, "error": "at instruction 29 (SYSCALL): failed native call: at instruction 1861 (ABORT): ABORT"}
Should these log messages also show when I talk to the RPC server via invokescript or only for signed tx's?
So we have some defined behavior for runtime logs (they're available in node logs, but there is a chance that eventually we'll have something like neo-project/neo-modules#737) and we have neo-project/neo#2782 to track the potential protocol improvements (with neo-project/neo-vm#491). I think we don't have a lot left for this particular issue, so I'm closing it.