Toolchain and reproducibility baseline

The executable build foundation uses exact project-selected versions from tools/toolchain.toml and the committed root Cargo.lock. It preserves the Phase 0 Component Model evidence path and supplies maintained Protobuf RPC generation, centralized WIT bindings and test infrastructure for the current runtime and completed Phase 2 delivery surface. Toolchain and code-generation steps are separate from the explicit standalone node startup command.

See build-foundation.md for generation ownership, focused commands, test utilities, dependency-cycle validation, and the clean-checkout Phase 1 sequence.

Selected versions

Area	Version	Purpose
Rust toolchain	1.97.1	Default formatter, compiler, Clippy, tests, code generation, and component build
Rust MSRV	1.94.1	Oldest compiler checked for all native workspace targets
Rust binding-check target	wasm32-wasip2	Compile generated Rust guest bindings against Preview 2
Rust component-core target	wasm32-unknown-unknown	Build self-contained cores before explicit componentization
Tokio	1.53.1	Fixed node runtimes, async adapters, and explicit test runtimes
Prost	0.14.4	Generated Protobuf message implementation
Tonic / tonic-prost	0.14.6 / 0.14.6	Generated RPC clients, servers, and Prost codec
tonic-prost-build	0.14.6	Build-time Rust generation from every authoritative .proto
protoc-bin-vendored	3.2.0	Pinned cross-platform protoc; no ambient compiler lookup
Tracing / tracing-subscriber	0.1.44 / 0.3.23	Structured instrumentation baseline and compile probe
Wasmtime	47.0.4	Generic Component Model runtime and retained Phase 0 compatibility facade
wit-bindgen	0.62.0	Guest bindings and canonical ABI exports generated from WIT
Serde / serde_json	1.0.229 / 1.0.150	Rust contract serialization
TOML	1.1.4	Configuration parsing and serialization
BLAKE3 / SHA-256	1.8.7 / 0.10.9	Cache/prepared identity and artifact digest verification
Clap / tempfile	4.6.4 / 3.27.0	CLI surfaces and test-only temporary storage
wasm-tools	1.254.0	WIT parsing, validation, componentization, and interface extraction
Buf	1.72.0	Protobuf linting and independent descriptor-set generation
Python / jsonschema	3.13.5 / 4.26.0	Repository and Draft 2020-12 schema validation
Go / Node / TypeScript / .NET	1.27.1 / 24.19.0 / 7.0.2 / 8.0.425	Cross-language interfaces and bounded native clients
Eclipse Temurin JDK	25.0.4.1+1	Java SDK build and runtime qualification; Java 25 minimum runtime
Gradle (optional Java build)	9.1.0	Java 25-compatible Gradle path; distribution SHA-256 pinned in tools/toolchain.toml
Zig / Clang / C target	0.16.0 / 21.1.0 / x86_64-linux-gnu	Pinned C11 header smoke test

Workspace dependencies are exact requirements and workspace crates consume them with workspace = true. Cargo ignores SemVer build metadata in requirements, so TOML is pinned as =1.1.4; the resolved package may display 1.1.4+spec-1.1.0 in Cargo.lock.

Shell completion tests

The Linux CLI completion suite executes generated scripts in Bash and Fish. Install both shells before cargo test -p latent --test completions; on the Ubuntu CI image, Fish is installed with apt-get install fish. The regression also passes with Fish 3.6.0. No interactive shell profile is loaded or changed. Generating Zsh or PowerShell output alone does not qualify its execution.

Java 25 SDK baseline and migration

The Java SDK now targets Java 25, including generated protocol classes, tests and packaged SDK classes. Java 21 cannot load the new SDK JAR. Consumers must upgrade their application build/runtime to Java 25 before adopting it; changing only the CI launcher while retaining --release 21 is not this migration. The minimum class-file runtime is Java 25, while repository qualification uses the exact Temurin patch/build above. This does not qualify every later JDK, Android or a Java guest runtime, and does not change the public SDK or wire API.

Set JAVA_HOME to that Temurin installation and put its bin first on PATH. The standalone helper chooses JAVA_HOME, or resolves java from PATH when it is unset, then uses that one installation's javac, java and jar. A wrong explicit installation fails rather than falling back. Both the compiler's own runtime and the runtime launcher must match the exact vendor and build; only the Temurin -LTS suffix is normalized. Every probe retains its 30-second limit. Gradle disables automatic discovery/downloads and uses JAVA_HOME with the same exact identity check and explicitly selected execution launcher.

tools/toolchain.toml distinguishes runtime 25.0.4.1+1 from the exact actions/setup-java selector 25.0.4+101.0.LTS. Adoptium's SemVer metadata encodes the fourth version component as 100 * patch + build; here it is 101. Do not substitute a floating major, omit the build metadata, or pass the four-component runtime string as a SemVer selector. See the Temurin release and Gradle compatibility matrix. Gradle 9.1.0 is the pinned CI version; Java 25 requires Gradle 9.1.0 or newer. CI verifies the distribution against the committed SHA-256 before extraction.

From the repository root, with the selected JDK and Python available:

python3 sdk/java-client/tools/java_toolchain.py check
python3 -m unittest tools.tests.test_check_tool_versions tools.tests.test_java_toolchain
python3 sdk/java-client/tools/generate_bridge.py --check
python3 sdk/java-client/tools/build.py test
python3 sdk/java-client/tools/build.py build
python3 sdk/java-client/tools/java_toolchain.py classes sdk/java-client/build/latent-java-client.jar
# Optional separate build path; JAVA_HOME must identify the selected Temurin JDK.
gradle --no-daemon -p sdk/java-client clean check

Standalone builds do not require Gradle or Maven. Both paths verify every SDK class header as major 69, minor 0, rejecting empty outputs, Java 21 classes and preview bytecode. Existing locked dependencies and generators are unchanged. The small Python tests use mocked probes and synthetic class headers; they are not evidence of Java compilation or a real-node transport run.

The existing SDK CI job executes Gradle and standalone semantic/transport/JAR checks on ubuntu-24.04 and retains java-sdk-qualification-<source-sha> with source/JDK/Gradle/OS identities, logs, class-file checks and the standalone JAR digest. The existing repository-contract job runs the Java participant in the separate-node provider workflow, retaining its receipts in the existing phase-1-bounded-conformance-<source-sha> artifact. Use successful results from the same reviewed source revision; configuration alone is not a qualification pass. Historical Java 21 release documentation and retained Windows tests compiled with --release 21 remain historical evidence, not Java 25-targeted Windows qualification. No milestone or phase gate is added.

Reproducibility boundary

CI uses ubuntu-24.04, not a floating runner label. Rust, contract tools, and language compilers are installed at the exact versions above. tools/check_tool_versions.py validates installed SDK compilers. Each SDK version probe has a 30-second timeout so a non-responsive local tool fails validation instead of blocking indefinitely. TypeScript is pinned in both package.json and package-lock.json and installed with npm ci.

Rust Protobuf generation uses protoc-bin-vendored; the build does not depend on a runner or workstation protoc. The exhaustive api/proto/latent-api.protos manifest and foundation validator prevent undeclared input drift. Generated RPC and WIT source is written only to Cargo OUT_DIR and is recreated from authoritative inputs on each clean build.

The echo build removes ambient Rust flags and target-directory overrides from child Cargo processes, disables incremental compilation, fixes release settings, uses the committed lockfile, builds a wasm32-unknown-unknown core, wraps it with the pinned wasm-tools, validates the result, and rejects interface drift. make echo-capsule-reproducibility performs two isolated clean builds and compares complete component bytes.

The Phase 0 reproducibility claim remains same-checkout, same-host, pinned-toolchain byte identity. Cross-platform byte identity is not claimed. The retained native collector receipt and benchmark evidence are documented in Phase 0 completion.

Clean-checkout validation

The supported reference environment is Linux or WSL. Install the selected toolchains, create the Python environment, then run:

python3.13 -m venv .venv
. .venv/bin/activate
python -m pip install --requirement tools/requirements.lock
make validate

make validate executes formatting, locked workspace checks, Clippy, tests, repository/foundation/contract validation, retained echo and containment integration, and all SDK compilation. make phase1-foundation runs the Rust and contract subset. A missing or stale Cargo.lock fails all locked commands.

Routine PR CI runs maintained runtime contracts, SDK checks and retained evidence validators. The Phase 0 executable collectors and their workflows are retired; historical receipts remain checked in. See CI ownership. Fresh Phase 2 evidence uses the bounded commands in offline validation and the operator walkthrough.

The MSRV check is reproducible with:

rustup toolchain install 1.94.1 --profile minimal
cargo +1.94.1 check --workspace --all-targets --all-features --locked

Install the remaining contract tools at their selected versions, for example cargo install wasm-tools --version 1.254.0 --locked and Buf 1.72.0. The Rust toolchain file installs rustfmt, Clippy, wasm32-wasip2, and wasm32-unknown-unknown.

Linux and evidence boundary

Linux or WSL may run make validate. Historical Phase 0 calibration, profiling and resource-soak commands belong to their recorded source revisions; their wrappers required a clean native-Linux host or VM and rejected WSL and containers because their measurements established a native-host reference. The separate Phase 1 collectors record their actual supported environment. The completed extension comparisons, including Docker and Kubernetes, ran on the documented Docker Desktop/WSL2 host. They are valid for that measured environment and do not replace the Phase 0 native baseline or claim bare-metal/cloud capacity.

Before a full authorization attempt, verify:

git status --porcelain --untracked-files=all

The retained August 30 Phase 0 receipt records an authorized pass for its canonical execution identity. It remains historical evidence; the build foundation does not modify the measured thresholds or results.

Generated-output policy

The Wasmtime security baseline records the 47.0.4 advisory scan, native-loader review and runtime/compiler upgrade requirements.

Handwritten Rust, WIT, Protobuf, JSON Schema, examples, and SDK sources remain authoritative. Generated build products normally live in Cargo OUT_DIR, target/contracts/, target/capsules/, and SDK compiler directories. The type-only codec fixture described below is an explicit checked-in exception:

• crates/latent-rpc/build.rs generates all Protobuf messages, clients, servers, and the embedded descriptor set;
• crates/latent-component-bindings/build.rs stages the aggregate runtime and echo WIT worlds and emits shared host/guest binding invocations;
• the maintained echo, containment, generic, and capabilities fixtures generate canonical ABI exports in their final guest crates from authoritative WIT;
• tools/build_echo_capsule.py emits the validated component, extracted interface, computed digest, generated manifest, typed contracts.json, deployment.json, input.json, and build receipt;
• tools/stage_runtime_wit.py, wasm-tools, and Buf emit validation artifacts under target/contracts/.

Executable capsule binaries and generated transport source are not checked in. The small crates/latent-wasmtime/src/values/types.wasm fixture contains Component Model type declarations for codec unit tests and is regenerated from adjacent types.wat. tools/validate_contracts.sh parses that source using pinned wasm-tools, compares the generated bytes with the checked-in fixture, and validates the result. This fixture check does not extend the historical echo reproducibility claim to other hosts or toolchains. The foundation validator continues to check authority boundaries, generation ownership, exhaustive Protobuf inputs, and the absence of superseded duplicate build scripts.

Allocation boundary

Build and validation code starts compiler/validator subprocesses only when a command explicitly runs. Linking generated bindings creates no engine, store, listener, socket, process, service thread, execution cell, or service-owned async runtime. latent-testkit::block_on polls on the calling thread; AsyncTestRuntime is explicitly constructed for tests and uses Tokio's current-thread scheduler without a worker pool.

Phase 3 guest contract tools

The full contract gate also builds the Rust guest SDK examples and the C canonical ABI fixture. Install the pinned wit-bindgen 0.60.0 CLI and Zig 0.16.0 alongside the existing Rust, Python and wasm-tools pins. On Linux x86_64, python3 tools/install_guest_bindgen.py "$HOME/.local/lsf-guest-tools" installs the SHA-verified upstream generator into a new directory; add that directory to PATH. CI uses this same verifier and the existing pinned Zig setup action. The installer refuses to overwrite an existing executable.

Generated source, components and observations stay under the selected target root. See the guest SDK workflow for build, signed admission and actual Rust/C runtime checks.