xcode-build-benchmark

1# Xcode Build Benchmark
2 
3Use this skill to produce a repeatable Xcode build baseline before anyone tries to optimize build times.
4 
5## Core Rules
6 
7- Measure before recommending changes.
8- Capture clean and incremental builds separately.
9- Keep the command, destination, configuration, scheme, and warm-up rules consistent across runs.
10- Write a timestamped JSON artifact to `.build-benchmark/`.
11- Do not change project files as part of benchmarking.
12 
13## Inputs To Collect
14 
15Confirm or infer:
16 
17- workspace or project path
18- scheme
19- configuration
20- destination
21- whether the user wants simulator or device numbers
22- whether a custom `DerivedData` path is needed
23 
24If the project has both clean-build and incremental-build pain, benchmark both. That is the default.
25 
26## Worktree Considerations
27 
28When benchmarking inside a git worktree, SPM packages with `exclude:` paths that reference gitignored directories (e.g., `__Snapshots__`) will cause `xcodebuild -resolvePackageDependencies` to crash. Create those missing directories before running any builds.
29 
30## Default Workflow
31 
321. Normalize the build command and note every flag that affects caching or module reuse.
332. Run one warm-up build if needed to validate that the command succeeds.
343. Run 3 clean builds.
35…