bug: Unknown Hint: Core(Core(EvalCircuit
Opened this issue · 3 comments
Current behavior:
Hint fails with:
Unknown Hint: Core(Core(EvalCircuit { n_add_mods: Deref(CellRef { register: AP, offset: -6 }), add_mod_builtin: Deref(CellRef { register: FP, offset: -6 }), n_mul_mods: Deref(CellRef { register: AP, offset: -4 }), mul_mod_builtin: Deref(CellRef { register: FP, offset: -5 }) }))
This happens presumably any time mul_mod is called. The problem is that this is not handled in cairo-vm.
Expected behavior:
Hint should succeed.
Steps to reproduce:
Run prove_block against affected blocks such as 160035, 160045, 160068, 160074, 160084, or 160093
I started by handling the hint in cairo-vm: Moonsong-Labs/cairo-vm#44
But this led to an error shortly later: Unknown memory cell at address 13:6
It turns out there is some logic missing from cairo-vm's fill_memory as compared to cairo-lang's. This comment (although unclear no me) suggests what is wrong:
# Note that we can't read 'n' here because sierra expects this function to compute it.A naive attempt to avoid reading n, as suggested in the comment mentioned above, isn't sufficient. It turns out there is a lot of extra code to calculate this value instead of reading it.
I began implementing this, but it turned into quite a rabbit hole, as there seems to be a lot more code omitted in the cairo-vm implementation. Even worse, a lot of the code that is omitted is actually dead code, so it's not obvious what exactly actually needed among the missing code.
The implementation from cairo seems to work 🎉 We're now passing the following blocks:
160035, 160045, 160068, 160074, 160084