Setup integration tests agains local sequencer

[0x-r4bbit]

[3esmit]

For running the sequencer in tests we could have it as an dependency, however sequencer_service as dependency can work only as library/in-process sequencer, not as “Cargo builds dependency binary and test spawns it”. Cargo does not expose dependency binaries to tests.

Problem with dependency path:

• pulls full sequencer graph into this repo’s Cargo.lock
• compiles logos-blockchain-* crates during cargo test --features local-sequencer-tests
• still needs LOGOS_BLOCKCHAIN_CIRCUITS before Cargo compiles deps
• test code cannot set that env early enough for dependency build scripts

Best options:

1. Keep shell script: cleanest. Isolates clone/build/circuits/cache outside workspace dependency graph.

2. Switch to in-process dev dependency:

   • add optional sequencer_service = { git = ..., tag = "v0.2.0-rc3", features = ["standalone"] }
   • add optional tokio
   • test calls sequencer_service::run(config, 0).await
   • no shell script or separate process running
   • document LOGOS_BLOCKCHAIN_CIRCUITS=/path/to/circuits

Best option on current systems: keep a shell script to clone and build, unless we prefer dependency purity over lockfile/build-time cost.

[3esmit]

logos-co/scaffold solve this way:

• setup syncs pinned LEZ repo into scaffold cache.
• Before cargo build, it ensures LOGOS_BLOCKCHAIN_CIRCUITS exists/downloads matching circuits.
• Then runs:
  cargo build --release --features standalone -p sequencer_service
• localnet start spawns:
  target/release/sequencer_service
• It patches config into project state dir, tracks PID, logs output, waits for port readiness.

Key point: scaffold wraps Cargo with its own CLI. logos-scaffold build runs setup first, then project build. logos-scaffold run runs build, localnet, wallet, deploy.

[0x-r4bbit]

setup syncs pinned LEZ repo into scaffold cache.
Before cargo build, it ensures LOGOS_BLOCKCHAIN_CIRCUITS exists/downloads matching circuits.
Then runs:
cargo build --release --features standalone -p sequencer_service
localnet start spawns:
target/release/sequencer_service

Can we do the same thing? The one thing to keep in mind is, if we need the circuits, I believe those are in a private repo atm.
However, if we end up pulling them in, we might also be able to get rid off the custom idl-gen tool in CI (which exists because installing spel requires the circuits which were unavailable back then)