VM fails when running particular Cairo1 programs

[MaksymMalicki]

Describe the bug
While trying to run the VM using particular Cairo1 programs, I get panic errors for two of them, and an execution error for one of them. Below, I listed the Cairo1 programs, which are failing for me, with the error, that the CLI produces. The last listed program is implemented by me, with the help of a LLM.

1. https://github.com/NethermindEth/cairo-vm-go/blob/main/integration_tests/cairo_1_programs/serialized_output/with_input/array_input_sum__small.cairo - execution mode and proofmode

cargo run array_input_sum__small.cairo --trace_file trace_output --memory_file memory_output --layout small --args "[444 555 666 777]"
Error: Run panicked with: [29721761890975875353235833581453094220424382983267374 ('Option::unwrap failed.')]

cargo run array_input_sum__small.cairo --trace_file trace_output --memory_file memory_output --layout small --args "[444 555 666 777]" --proof_mode --air_public_input air_public_input.json
Error: Run panicked with: [1 (''), 29721761890975875353235833581453094220424382983267374 ('Option::unwrap failed.')]

2. https://github.com/NethermindEth/cairo-vm-go/blob/main/integration_tests/cairo_1_programs/serialized_output/with_input/tensor__small.cairo - execution mode and proof mode

cargo run tensor__small.cairo --trace_file trace_output --memory_file memory_output --layout small --args "[5 4 3 2 1]"
Error: Run panicked with: [29721761890975875353235833581453094220424382983267374 ('Option::unwrap failed.')]

cargo run tensor__small.cairo --trace_file trace_output --memory_file memory_output --layout small --args "[5 4 3 2 1]" --proof_mode --air_public_input air_public_input.json
Error: Run panicked with: [1 (''), 29721761890975875353235833581453094220424382983267374 ('Option::unwrap failed.')]

3. https://github.com/NethermindEth/cairo-vm-go/blob/main/integration_tests/cairo_1_programs/with_input/proofmode_segment_arena__small.cairo - execution mode and proof mode

cargo run proofmode_segment_arena__small.cairo --trace_file trace_output --memory_file memory_output --layout small --args "[1 2 3 4 5]"
Error: VirtualMachine(CantWriteReturnFp((RelocatableValue(Relocatable { segment_index: 6, offset: 5 }), RelocatableValue(Relocatable { segment_index: 1, offset: 4 }))))

cargo run proofmode_segment_arena__small.cairo --trace_file trace_output --memory_file memory_output --layout small --args "[1 2 3 4 5]" --proof_mode --air_public_input air_public_input.json
Error: Error: VirtualMachine(CantWriteReturnFp((RelocatableValue(Relocatable { segment_index: 8, offset: 5 }), RelocatableValue(Relocatable { segment_index: 1, offset: 5 }))))

To Reproduce
Steps to reproduce the behavior:

1. Go to ./cairo1-run
2. Run the VM, using the commands listed in the description

Expected behavior
The VM should not fail on those Cairo1 programs.

What version/commit are you on?
Version: v2.0.0, Commit: 60c1fa0

[JulianGCalderon]

Hi! @MaksymMalicki. I've been taking a look a this issue.

In the first program, the issue seems to be in the input arguments. Arrays are serialized as [length, elements...]. For example, to represent (444, vec![555], 666, vec![777]), you would need to specify as arguments: [444, 1, 555, 666, 1, 777], although this will later fail due to index out of bounds. The following input arguments returns without errors: [0, 1, 555, 0, 1, 777].

Let me know if this helps you.

[FrancoGiachetta]

The second program seems to have the same error as the one stated above. Calling it with something like this:
cargo run program.cairo --trace_file trace_output --memory_file memory_output --layout small --args "[1 2 2 4 5]"
Solves the issue.

[JulianGCalderon]

On first sight, the third error seems to be related to #1870.

[MaksymMalicki]

Thank you! This clears things up.

I belive this cairo1 program is not executing properly: https://github.com/NethermindEth/cairo-vm-go/blob/main/integration_tests/cairo_1_programs/keccak.cairo

I use: cargo run keccak__small.cairo --layout all_cairo

[FrancoGiachetta]

Hi there! Could you provide the error with that program?

[FrancoGiachetta]

Hi @MaksymMalicki! I have a few updates.
Firstly, the third failing program you sent seems to be resolved with this PR. It needs to be reviewed yet, but perhaps you want to give it a try in the midtime. Secondly, the last error you sent is due to a hint, which is Starknet::SystemCall, that is not implemented in the cairo-vm and so it fails to recognise it.

[FrancoGiachetta]

Hi @MaksymMalicki! Just wanted to notify you that the PR I've mentioned, which solves the issue with third program, has just been merged. With that, I think there's no other issue here (apart from the fourth program which is actually not an error, hints related to syscalls are not implemented in cairo-vm).
Let us know if you need anything else!

[FrancoGiachetta]

Closing this issue since there are no other bugs. Let us know wether you need anything else!

[MaksymMalicki]

Great Franco, this helped a lot! 🙏