Nim hash not updated in nimble.nix

[ekimber]

Describe the bug
There's a comment in the file nix/nimble.nix :

WARNING: Requires manual updates when Nim compiler version changes.

It looks like it wasn't updated, resulting in a hash mismatch

error: hash mismatch in fixed-output derivation '/nix/store/fzkjrmna2fxl540g3mxgc8jqf1v41d8v-source.drv':
specified: sha256-sa0irAZjQRZLduEMBPf7sHlY1FigBJTR/vIH4ihii/w=
got: sha256-MVHf19UbOWk8Zba2scj06PxdYYOJA6OXrVyDQ9Ku6Us=
error: 1 dependencies of derivation '/nix/store/gd7dgkqnmp2kkkf1wpqjdj598bqna2ha-nimbus-eth2-24.12.0-4e440277.drv' failed to build

To Reproduce

1. Run a nix build using the nimbus-eth2 flake as an input
2. Get a hash mismatch

Additional context
@jakubgs since you commented in the ethereum.nix repo. The flake is great and makes everything super easy! I don't know what to suggest here though, obviously it is trivial to fix the hash but it's going to be missed again unless there's a CI test to catch it.

[tersec]

There are Nix CIs and they seem to be running fine:

• custody subnet count decoding during discovery #6777
• rm daily (not nightly) GitHub Actions workflow #6786
• restore electra aggregate gossip validation to parity #6787

But it's possible there are issues here.

[tersec]

Does

• switch to Nim v2.0.14 #6795
  resolve this?

[ekimber]

Does

• switch to Nim v2.0.14 #6795
  resolve this?

Yes this is fixed now 👍

I can't see any nix in the CI but it's not something I'm familiar with

[jakubgs]

Indeed, I was able to reproduce this on our linux-05 CI host when building from stable:

jenkins@linux-05:~/nimbus-eth2$ nix build --print-build-logs '.?submodules=1#'
source> trying https://github.com/nim-lang/nimble/archive/46e2ae13eeb95619a371a74d16efc5aff30ea371.tar.gz
source>   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
source>                                  Dload  Upload   Total   Spent    Left  Speed
source>   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
source> 100  618k    0  618k    0     0   782k      0 --:--:-- --:--:-- --:--:--  782k
source> unpacking source archive /build/46e2ae13eeb95619a371a74d16efc5aff30ea371.tar.gz
error: hash mismatch in fixed-output derivation '/nix/store/fzkjrmna2fxl540g3mxgc8jqf1v41d8v-source.drv':
         specified: sha256-sa0irAZjQRZLduEMBPf7sHlY1FigBJTR/vIH4ihii/w=
            got:    sha256-MVHf19UbOWk8Zba2scj06PxdYYOJA6OXrVyDQ9Ku6Us=
error: 1 dependencies of derivation '/nix/store/hgciddz73gz31kj0lla1ca2qpbxx3jv9-nimbus-eth2-24.12.0-4e440277.drv' failed to build

But the issue no longer exists in unstable.

[tersec]

Indeed, I was able to reproduce this on our linux-05 CI host when building from stable:

jenkins@linux-05:~/nimbus-eth2$ nix build --print-build-logs '.?submodules=1#'
source> trying https://github.com/nim-lang/nimble/archive/46e2ae13eeb95619a371a74d16efc5aff30ea371.tar.gz
source>   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
source>                                  Dload  Upload   Total   Spent    Left  Speed
source>   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
source> 100  618k    0  618k    0     0   782k      0 --:--:-- --:--:-- --:--:--  782k
source> unpacking source archive /build/46e2ae13eeb95619a371a74d16efc5aff30ea371.tar.gz
error: hash mismatch in fixed-output derivation '/nix/store/fzkjrmna2fxl540g3mxgc8jqf1v41d8v-source.drv':
         specified: sha256-sa0irAZjQRZLduEMBPf7sHlY1FigBJTR/vIH4ihii/w=
            got:    sha256-MVHf19UbOWk8Zba2scj06PxdYYOJA6OXrVyDQ9Ku6Us=
error: 1 dependencies of derivation '/nix/store/hgciddz73gz31kj0lla1ca2qpbxx3jv9-nimbus-eth2-24.12.0-4e440277.drv' failed to build

But the issue no longer exists in unstable.

stable uses Nimble 0.16.2, while unstable uses Nimble 0.16.4. They require different build setups, and obviously have different hashes. It's not intended for the Nix derivation in unstable now to apply to stable, only unstable. After the next release, the mismatch should vanish.

[jakubgs]

Yeah, but there is clearly an issue with some Nix derivation caching that is causing us to miss when the hash needs to be updated. Which normally is every time Nim is updated.