Released October 5, 2026
New
- Build and test capture – Build errors and failed tests now reach the assistant even when a long build’s output is truncated: the new
axbuildtool runs thexcodebuild,swift buildorswift testcommand you’d normally run, saves the full log and report, and returns a short summary with each error’s location and each failed test’s message and Swift Testing’s evaluated values. It ships in the Claude Code and Codex plugins (in Pi, put it on yourPATH; Cursor and MCP setups save build output to a file instead), andbuild-fixer,test-runnerand/axiom:fix-buildread its saved log before rebuilding.
Updated
- Derived Data and simulator cleanup – Deletes only the current project’s Derived Data folder, shuts down or erases only the affected simulator, and inspects a running build before stopping it. The change covers
build-debugging,xcode-debugging,swiftui-debugging,swiftui-debugging-diag,swiftui-previews-ref,app-store-diag,app-launchandsimulator-tester. - Also updated – A new temporary folder for each build and test run, so concurrent runs keep their own results, and an
app-launchclean-boot sequence that erases a simulator whether or not it was already shut down.
Changed
- Build cleanup approval –
build-fixerand/axiom:fix-buildnow stop before killing a build, deleting Derived Data or resetting a simulator, and return the cause, the evidence and the exact command to approve.
Full Changelog: v27.2.1...v27.3.0