> Documentation version: 3. [HTML page](nightly-compatibility.html) # Shared published-release compatibility The shared nightly answers one question: does the latest published product release work with the latest Roc nightly on every supported release target? Consumers use ` .github/workflows/nightly-compatibility.yml ` at a reviewed full SHA. Their caller supplies the schedule and native prerequisites; the shared runner owns selection, archive validation, compilation, execution, diagnostics and reporting. Compiler-pin changes belong to maintainers during downstream pull-request work. This nightly does not change pins, open upgrade pull requests, merge changes, publish releases or test unreleased development examples. ## Risks and controls for compatibility verdicts Independent moving lookups can test different release/compiler pairs, and one passing target can hide another target’s failure or missing result. Resolve the pair once and require complete matching evidence. The shared runner verifies asset identity, runs the immutable suite, and aggregates every declared target for the same run and attempt. Missing or interrupted evidence cannot close the compatibility issue. Launch errors remain setup failures rather than synthetic exit codes that a case could accept; signal termination cannot match an ordinary exit expectation. Header admission checks actual dependency fields, ignoring comments and rejecting compiler constraints or ambiguous syntax. Regression fixtures cover these states and hosted tests exercise native execution. The dashboard is a dated snapshot; a stopped publisher cannot update its colour. A pass covers the declared examples and targets only. Fuzzing builds may add only the admitted ` --fuzz ` switch; archived metadata cannot replace the compiler, output path or other compiler arguments. Cases with unstable fuzzer statistics explicitly opt out of stderr comparison while preserving its raw bytes. Stdout and the normal exit code remain assertions. Signals, timeouts and output limits cannot satisfy an expected failure code. Regression tests cover these boundaries, and hosted Linux and Apple Silicon smoke tests exercise a published fuzzing platform with clean replay, one-second search and an expected exit 77. ## Configure the caller Keep one caller for the product release suite. A Roc package uses one Linux runner. A platform names every supported release runner. One archive can cover several bundles through its declared release dependencies. ``` yaml name: Nightly compatibility on: schedule: - cron: '17 13 * * *' workflow_dispatch: inputs: nightly-tag: type: string default: '' release-tag: type: string default: '' permissions: {} jobs: compatibility: permissions: contents: read issues: write uses: lukewilliamboswell/roc-automation/.github/workflows/nightly-compatibility.yml@REVIEWED_FULL_SHA with: nightly-tag: ${{ inputs.nightly-tag || '' }} release-tag: ${{ inputs.release-tag || '' }} runners: '["ubuntu-24.04"]' ``` The permission ceiling permits the separate report job. Selection, tests and aggregation reduce it to ` contents: read `; only reporting has ` issues: write `. No secrets are inherited. The caller runs only on schedule or manual dispatch on the actual default branch. The shared concurrency group serializes runs, so an older failure cannot race a newer passing report. ` runners ` accepts a unique, non-empty JSON array drawn from ` ubuntu-22.04 `, ` ubuntu-24.04 `, ` ubuntu-24.04-arm `, ` macos-15 `, ` macos-15-intel `, ` macos-26 `, ` windows-2022 ` and ` windows-2025 `. ` macos-15-intel ` runs the ` x64mac ` target natively, and the Windows labels run native x64 executables. Name the complete release matrix: a target no runner executes contributes no evidence, so it is cross-compiled only. Windows uses the same archive admission, compiler diagnostics, case deadlines and aggregate evidence contract as Linux and macOS; the runner adds the native ` .exe ` suffix automatically. Independent internal pins can select an old engine or an installer without the consumer’s reviewed Blueprint checksums even when current source tests pass. The shared workflow and its composite action use ` $/actions/... ` references, which GitHub resolves from the containing file’s repository and commit, without checking out workspace files. The consumer’s one full workflow SHA therefore fixes selection, execution, aggregation, the installer registry and reporting. A consumer cannot shadow these actions with files in its checkout. External actions retain full SHA pins. Source regressions enforce this composition; hosted consumer tests exercise the real nested installation and archived games. Unknown Blueprint versions and wrong digests still fail admission. This workflow targets GitHub.com; self-repository references are unavailable on GitHub Enterprise Server. A complete native runtime verdict is still required for compatibility. For native prerequisites, ` setup-command ` is a JSON argv array, for example ` ["blueprint", "run", "nightly-prerequisites"] `. It runs from the event commit’s checkout in the read-only test job; it must provision dependencies, not rebuild the package or replace archived examples. ` install-blueprint: true ` installs the consumer’s verified Blueprint; ` install-nix: true ` explicitly enables Nix for an environment that needs it. Leave both false for a runner that needs neither. Toolchain installation precedes the prerequisite command. Windows prerequisites must use native tools through ` setup-command `, such as a checked-in Python setup script. Nix is not a Windows prerequisite backend. Requesting either shared installer on Windows fails explicitly. For a mixed matrix, keep both installers disabled and let a portable setup script select the native provisioning steps for each operating system. A prerequisite failure is a setup failure, never a compatibility pass. ` test-environment ` is a JSON array of public name/value records, for example ` [{"name":"DISPLAY","value":":99"}] `, for a headless native test environment. Reserved compiler, cache and Actions variables cannot be overridden. Names and duplicates are checked without regard to case, including Windows ` Path `, ` PATHEXT `, ` SystemRoot ` and ` COMSPEC `. These values are not secrets. Setup scripts must arrange any display server’s lifetime and redirected output explicitly; exporting a variable inside the setup child does not change the runner’s environment. The action has a fixed 300-second compiler deadline, a 600-second prerequisite deadline and a default 10-second deadline per example case. ` case-timeout-ms ` can select 1–120000 milliseconds. The matrix job has a 60-minute overall limit. Each command has a 10 MB capture budget; timeout and output-limit results keep the partial bytes captured before cancellation and terminate child processes. On Windows, basic-cli manages the complete child tree in a Windows Job Object; on Unix, it manages a process group. CI tests that a timed-out example cannot leave a descendant running, alongside successful compilation and execution with the real compiler on both supported Windows images. The compiler and every example run without ` GH_TOKEN ` or ` GITHUB_TOKEN `. ## Keep compatibility cases bounded The archived cases verify published behavior and expected output. A package that demonstrates fuzzing or benchmarks supplies a small smoke mode for those examples, with at most one second of workload execution per target. That budget excludes compiler checks and builds. The runner’s default ten-second case deadline is a safety limit for ordinary examples, not a recommended fuzzing duration or permission to put a campaign in the suite. An interrupted case is incomplete evidence, even if it ran for its allotted wall time. Routine PR CI verifies working-tree builds and smoke execution. This shared nightly verifies the published release on the selected compiler. Sustained fuzz searches and statistically meaningful benchmark runs belong in separate schedule/manual jobs, as [Fuzzing](optional-workflows.md#fuzzing) and [Benchmarks](optional-workflows.md#benchmarks) describe. Their failures remain visible in their own runs; they neither replace nor alter this runner’s compatibility verdict. In particular, a daily search of Roc builtins can catch upstream regressions without making release examples run a ten-minute campaign. ## Select one immutable pair The selection job resolves the latest Roc nightly and the most recently published final numeric product release, such as ` 0.13.2 ` or ` v1.2.3 `. It excludes drafts, prereleases and auxiliary tags such as ` tools-* `, ` runtime-* ` and ` linker-inputs-* `. Release lists are paginated; an incomplete listing is an error. All targets receive the same ` selection.json `, never separate moving lookups. Compiler execution verifies the installed version names that nightly. The selected release must contain exactly one ` -examples-.zip `. ` package-name ` defaults to the repository name. Missing examples on the newest product release are an error, not permission to silently test an older product release. A repository with no final release has no compatibility result; its workflow fails selection with the reason visible in the log and does not modify the compatibility issue. Selection records the release ID, asset ID, length and GitHub’s SHA-256 digest. Targets download by that asset ID and check length and digest before extracting or executing anything. This binds the tested bytes to that selection; GitHub release metadata is not an independent provenance attestation. Roc verifies the content identities in the archived dependency URLs when fetching bundles. Manual ` nightly-tag ` or ` release-tag ` inputs reproduce a historical combination. A run with either override never opens or closes the issue about the latest pair. Use ` report-issue: false ` for an explicit diagnostic-only caller. ## Publish the suite contract Build and test the same archive before publishing it, as [Build and test the exact archive](examples.md#build-and-test-the-exact-archive) describes. The canonical ZIP has one root named after its filename without ` .zip `, ordinary Unix regular files and directories, and these contents: ``` text -examples-/ README.md spec.json examples/ main.roc ... sibling modules and data ... ``` Every member stays under that root. Links, traversal, duplicates, encrypted members, file/directory collisions and ambiguous filenames are rejected before extraction. The ZIP is at most 50 MB, expands to at most 100 MB, and has at most 10000 members. Member paths use ASCII letters, digits, dots, underscores, hyphens and directory separators; no empty, ` . ` or ` .. ` component is allowed. ` spec.json ` is a versioned, explicit test plan. Required case fields remain explicit even when their value is empty: ``` json { "schema_version": 1, "release": "1.0.0", "dependencies": [ "https://github.com/owner/package/releases/download/1.0.0/CONTENT_HASH.tar.zst" ], "apps": [{ "path": "examples/main.roc", "cases": [{ "name": "default", "args": [], "stdin": "", "stdout": "Hello!\n", "stderr": "", "exit_code": 0 }] }] } ``` ` release ` must match the selection. Dependencies are immutable published bundle URLs belonging to that repository and tag. Each application directly names at least one declared bundle in its header and has no compiler constraint: it must be able to meet a newer compiler without editing the archived source. The runner accepts canonical ` app [entrypoints] { alias: platform "URL", package: "URL" } ` headers, including whitespace and line comments. Dependency URLs in comments or application bodies do not count; duplicate fields, escaped header strings and unsupported header syntax fail admission. It never changes an archived file, substitutes the working-tree bundle or runs a formatter. An empty package cache starts each target’s test. The suite contains 1–100 unique application paths under ` examples/ `, with 1–100 uniquely named cases per application. The runner checks and builds each application once with the selected compiler, then runs each recorded case and compares stdout, stderr and exit code exactly. A failed application does not prevent diagnostics for later applications. Declared cases are the execution inventory; maintainers review the suite for representative coverage before publishing it. Passing is not a claim of security compliance or complete API coverage. An application may add ` target `, such as ` wasm32 `, and ` run `, a JSON argv array for its runtime. Native applications omit both. A non-native target requires a runtime command containing ` {executable} `; ` {suite} ` names the extracted root. For example, a Wasm platform can supply ` "target":"wasm32", "run":["node","{suite}/runtime/check.mjs","{executable}"] `. The runtime helper and fixtures belong to the immutable archive; native setup installs its tools. The shared runner still owns checking, compilation, timeout, stdout/stderr capture and exact case comparison. The runtime must exercise the built artifact and exit after its assertions; merely building a cart or opening a window does not establish behavioral compatibility. An application may add ` build_args: ["--fuzz"] ` to link a fuzz target. Missing or empty ` build_args ` keeps the ordinary build; every other argument or duplicate is rejected. These arguments affect ` roc build ` only, never ` roc check `. Fuzz builds use ` --opt=speed `, since fuzz instrumentation requires the LLVM backend; ordinary examples keep ` --opt=dev `. A case may add ` stderr_match: "ignore" ` for unstable libFuzzer diagnostics, with ` stderr: "" `. Missing ` stderr_match ` or ` "exact" ` retains exact stderr comparison; other policies are rejected. Both streams are always captured and displayed, and stdout and the normal exit code are compared exactly in every mode. Seed replay also goes through libFuzzer and can print varying diagnostics. A target that must find a failure records ` exit_code: 77 `; a signal or interruption cannot match it. The working-tree ` test-examples --update ` command preserves the selected policy and leaves ignored stderr empty instead of recording volatile statistics. A case may add ` skip: {"reason":"...","issue":"https://github.com/..."} `. The app is still checked and built, and the skip is visible. Any skip prevents a complete pass and prevents closing the compatibility issue. Prefer a runnable headless test where possible. A suite with no executed cases is never compatible. ## Preserve diagnostics on happy and unhappy paths Compiler stdout and stderr are always displayed, including after exit code 0. Warnings remain nonfatal by default. Successful compilation does not imply that it was warning-free. The runner owns compiler execution instead of delegating it to a driver that might discard captured success output. Each target artifact, ` compatibility- `, retains raw stdout and stderr, command arguments, working directory, process status (normal exit, signal or I/O error), exit code, signal number, launch-error details, interruption flags and stdin, public environment, deadlines and expected output for failing cases. The ZIP inventory is retained too. Console rendering escapes workflow-command markers, carriage returns and terminal escapes; raw files preserve the original bytes. Compiler diagnostics and example stderr are separate: expected example stderr is compared with the case’s specification. The ` nightly-compatibility-summary- ` artifact contains ` summary.json `: the selected identities, per-target results, counts and aggregate verdict. The job summary links the meaning of the verdict to the diagnostic artifacts. Artifacts are retained for 14 days. Download useful evidence before retention expires; the run link and selected versions allow a later manual reproduction. | Result | Meaning | Follow-up | | --- | --- | --- | | ` compatible ` | Every target ran cases and passed, without skips | No compatibility action; review any compiler warnings | | ` incompatible ` | A compiler check/build or recorded example assertion failed | Inspect per-target diagnostics; fix the compiler/package issue and publish a compatible patch release when needed | | ` setup-failed ` | Selection, archive validation, prerequisites or target evidence failed | Repair setup or release packaging; rerun all jobs | | ` test-timeout ` / ` output-limit ` | Execution was interrupted; compatibility is unknown | Inspect partial logs; repair the hang/noise or adjust a justified deadline | | ` not-tested ` | Cases were skipped or no complete execution was established | Resolve the documented skips or missing work; rerun all targets | Test failures keep the workflow red after evidence is uploaded. Reporting a failure does not turn it green. Matrix fail-fast is disabled, so a failing target does not cancel the others. A missing, duplicate, stale-attempt or mismatched result cannot produce a passing aggregate. Rerun all jobs when retrying a matrix; a successful old target is not current-attempt evidence. Only an established compatibility failure opens or updates the one tracking issue. Only a complete current-attempt pass on every target closes it. Infrastructure failure, cancellation, timeout and skipped cases leave that issue alone. The privileged report job executes only the pinned shared reporting action; it receives outcome and selected tags, never archive diagnostics or repository code. ## Read the downstream dashboard The README’s compatibility column reads the fixed verdict gate of the newest eligible shared workflow, checks its immutable caller still uses the configured pin, and links to the run. Scheduled runs qualify. A default-branch manual run also qualifies when its successful shared ` Track release compatibility ` job proves both effective selectors were empty. The pinned job’s guard excludes historical release/compiler overrides. The dashboard validates its exact name, shared-workflow origin and run, attempt and source identities, alongside the verdict; a local lookalike job cannot establish this proof. The collector scans up to 50 recent runs in API order, skipping historical or otherwise unproven manual runs so they cannot hide an older eligible result. If none qualifies, the result stays unknown. A manual run with reporting disabled, failed reporting or setup failure before a reportable verdict has no selector proof and cannot replace eligible evidence. Empty selectors mean latest when selection ran, subject to the same 48-hour freshness window as scheduled runs. Verification requires the canonical single-job caller shown above: one literal job-level ` uses `, optional ` with ` and ` permissions `, and no local jobs, conditional or matrix on that call. Other caller shapes remain unverified. GitHub must record the exact resolved shared workflow path and SHA; every verdict job must belong to the same run, attempt and source SHA. Job and step display names alone cannot establish the origin of a verdict. Each snapshot marks passes older than 48 hours stale. This age check runs at publication time: if Documentation stops deploying, static badges retain their last colour. Check the snapshot date and investigate publication when it is over 48 hours old before relying on a green result. Development CI, pin-updater success and weekly floating-input checks are outside this contract. An adoption or infrastructure message means compatibility has not been verified, and states the follow-up. Manual historical probes do not replace eligible results. The independent revision column tells maintainers which automation SHAs need review and upgrade. ## Run the utility directly The source entry point is ` scripts/release_compatibility.roc `, behind ` blueprint run release-compatibility -- `. The tools build also produces static Linux ` release-compatibility- ` executables; adoption of a released binary follows [Verify released artifacts](artifact-verification.md#verify-released-artifacts). New artifacts become available only when a maintainer releases the tools. The phases are ` select `, ` test ` and ` aggregate `, using the same ` RA_* ` environment contract as ` actions/release-compatibility/action.yml `. ` RA_DIRECTORY ` must be a new private directory for each invocation. ` select ` needs ` GH_TOKEN `, ` GITHUB_REPOSITORY `, ` RA_NIGHTLY `, ` RA_RELEASE `, ` RA_PACKAGE ` and ` RA_RUNNERS `. ` test ` needs ` RA_SELECTION `, ` RA_RUNNER `, the actual ` RA_COMPILER ` executable, ` RA_SETUP `, ` RA_ENVIRONMENT `, ` RA_CASE_TIMEOUT_MS `, ` RA_PYTHON `, ` RA_ARCHIVE_HELPER `, ` GITHUB_RUN_ID ` and ` GITHUB_RUN_ATTEMPT `. ` aggregate ` needs ` RA_SELECTION `, ` RA_ARTIFACTS `, ` RA_TEST_RESULT ` and the same run identity. ` GITHUB_OUTPUT ` is an existing output file; aggregation also writes ` GITHUB_STEP_SUMMARY `. The utility and action use ` gh ` and Python 3.10 or later on Linux, macOS and Windows. ` RA_PYTHON ` names the Python executable and ` RA_ARCHIVE_HELPER ` names the companion ` release-compatibility-archive.py ` artifact from the same tools release as the utility. Verify both files against that release’s admitted checksums. When running from source, use ` actions/release-compatibility/archive.py ` from the same reviewed commit instead. The Python standard library verifies SHA-256, inspects ZIP metadata and extracts regular bytes, avoiding platform-dependent shell archive tools. Archive admission rejects Windows device names, alternate data streams, trailing dots and case-insensitive file or parent-directory collisions on every host. No archived code is imported by the helper. The action builds the utility with its fixed tooling compiler before installing the selected floating package compiler; consumer Blueprint evaluation is optional and limited to native prerequisite setup.