swiftpm-build-inspector

SwiftPM Build Inspector

Bundled commands use $PLUGIN_ROOT ($env:PLUGIN_ROOT in PowerShell; same path suffix) for the plugin root. Set it once: use the host's plugin-root variable when defined (Claude Code: PLUGIN_ROOT="$CLAUDE_PLUGIN_ROOT"), otherwise the absolute path of this plugin's root directory.

Gather evidence before recommending package changes. Do not edit manifests/dependencies without explicit approval.

Inspect

• Package.swift, Package.resolved
• local vs remote packages
• build-tool/package plugins
• binary targets
• dependency layering, imports, cycles, oversized modules
• timing summaries/logs showing package work

Before recommending a local package, prove it is in the project graph: check XCLocalSwiftPackageReference and XCSwiftPackageProductDependency in project.pbxproj. Ignore on-disk packages that are not linked.

For branch-pinned dependencies:

python3 "$PLUGIN_ROOT/skills/swiftpm-build-inspector/scripts/check_spm_pins.py" --project App.xcodeproj

If tags exist, recommend tag pins when appropriate; otherwise recommend a revision hash for determinism. Distinguish intentional branch tracking from missing-tag upstreams.

Focus Areas

• graph shape and downstream rebuild scope
• plugin overhead in local/CI builds
• clean-environment checkout/fetch cost
• config drift causing duplicate module variants
• dependency direction violations and cycles; extract shared contracts into protocol/interface modules
• oversized modules (~200+ files)
• umbrella modules with @_exported import
• test targets depending on the app target instead of the module under test
• Swift macro or swift-syntax cascades
• multi-platform build multiplication (iOS/watchOS/tvOS/macOS variants)

Modular SDK migrations do not automatically speed builds. Compare SwiftCompile, SwiftEmitModule, and ScanDependencies task counts and benchmark before recommending for performance; note when the benefit is import hygiene/API surface rather than wait time.

If the same module appears multiple times in timing output, investigate option/variant drift before source shaving.

Report

For each finding include evidence, affected package/plugin, clean vs incremental impact, CI impact, estimated wait-time impact, and approval requirement. If the bottleneck is not package-related, hand off to xcode-project-auditor or xcode-compile-profiler.

References: references/spm-analysis-checks.md, ../../shared/build-optimization/references/recommendation-format.md, build-optimization-sources.md.