Release v0.18.0 · scalus3/scalus

Release Notes

Added

Scala 3 cross-build: scalus-plugin and scalus-core now compile on both Scala 3.3.7 (LTS) and 3.8.x. The plugin isolates the one diverging compiler-API call (phase registration) behind a version-specific PluginCompat trait; the remaining ~9.4k lines of dotty-internal API usage compile unchanged. The Native platform targets 3.8.3 while JVM/JS stay on 3.8.4, with version-conditional budget/size baselines for the cross-build
V3 == now routes to structural equality: non-structural types (Rational, AssocMap) are excluded from the Eq system (their given Eq is replaced with a compiletime.error and the plugin errors on Rational == / AssocMap ==, with RationalEq/AssocMapEq for explicit comparison), so every remaining Eq is structural; the V3 List/Option intrinsics (contains, indexOf, deleteFirst, distinct, diff, Option.contains) drop their dead Eq argument and compare via equalsRepr
Conway certificate mutators in scalus-cardano-ledger: StakePoolCertificatesMutator (Shelley/Conway POOL transitions — registration, re-registration into futureStakePoolParams, retirement) and VotingCertificatesMutator (Conway GOVCERT DRep register/unregister/update with deposit validation). SlotConfig gains epochLength/zeroEpoch plus epochOf/firstSlotOfEpoch so the current epoch is derived from the slot (mainnet zeroEpoch=208, preprod 4, preview
1-day epochs) instead of treating the slot number as an epoch
EvaluatorReportConfig — typed configuration for PlutusScriptEvaluator diagnostic output (output directory, artifact selection, profile level/outputs), overridable via the SCALUS_DUMP, SCALUS_DUMP_DIR, and SCALUS_PROFILE* environment variables; new PlutusScriptEvaluator.apply overload accepting it. The legacy debugDumpFilesForTesting: Boolean constructors are retained
and map onto it
profiling integrated into PlutusScriptEvaluator: when enabled (SCALUS_PROFILE=summary|full, SCALUS_PROFILE_OUT=…, or EvaluatorReportConfig.profile), each script's profile is rendered to the console or to per-script files. Output formats: a compact text summary, CSV, JSON, and a self-contained interactive HTML report — a tabbed UI with sortable/filterable tables and %-of-CPU bars, a "By Source Location" view with full source-position attribution and a recursive incoming-call tree, a call graph with inclusive (call-stack) cost and a Hot Paths tree showing where the budget flows from the entry point, a per-line cost-annotated source view (cross-linked from the location tables), and a transition-matrix heatmap with cost-weighted edges and a hot-edges table; the report title and per-entry fee are included
ProfileFormatter.toCsv / toJson / summary, and toHtml(data, sources) with source annotation; platform.createDirectories and platform.fileExists for cross-platform file I/O

Changed

Evaluator debug dumps now use stable, overwriting filenames (<scriptHash>-<language>-<tag>-<index>.flat) instead of the volatile script-<txid>-… names, so fee-balancing re-evaluations overwrite rather than accumulate duplicate files; the per-builtin budget log is truncated once per evaluation (previously appended without bound) and renamed to budget.log; a manifest.json describing every dumped script is written alongside (#93)
dependency updates: Yaci DevKit 0.4.4, cardano-client-lib/backend-blockfrost 0.7.2, jsoniter-scala 2.38.14, dotty-cps-async 1.3.3, jackson-databind 2.21.4, Scala Native libs 0.5.12, sttp client4 4.0.25, slf4j 2.0.18; security bumps for brace-expansion (CVE-2026-45149) and vitest (CVE-2026-47429) in scalus-site

Fixed

EtaReduce free-variable check had no cases for Case/Constr terms, so λx.(f x) was eta-reduced even when f referenced x inside a Case/Constr — dropping the binder and leaving x unbound; it now uses the canonical TermAnalysis.freeVars. Surfaced on Scala 3.8.x (Knights depthSearch lowering); latent on 3.3.x where the shape did not arise
TxBuilder now accepts permissionless script stake-credential registration (registration is witness-free in the Conway ledger) instead of rejecting it as a credential/witness-type mismatch, while still honoring an explicitly attached script/native witness
conformance vectors now run in cardano-ledger's Imp slot/epoch environment