Dependencies & post-hooks

Use case: order work correctly — some tasks must run before, and some after, a task — and diagnose failures automatically.

Demonstrates: dependencies, post-hooks, failure hooks · Guide: Dependencies

Prerequisites: none

Run it

rune deploy

Expected output

building
testing
deploying
notify: deployed ✓

deploy: build test && notify — build and test are dependencies (run first); notify is a post-hook (runs after deploy succeeds). Each task runs at most once per invocation.

Then try the failure hook — rune flaky fails on purpose and runs its post-mortem:

checking
diagnosing: diagnose
diagnose: flaky failed with exit 3

The invocation still exits non-zero (hooks never change the exit code), and over MCP the diagnostic reaches the agent as a fix suggestion in the same tool response.

How it works

See the Runefile: prerequisites go after the colon, post-hooks after &&, failure hooks after ||. The hook body reads RUNE_FAILED_TASK and RUNE_FAILED_EXIT_CODE from its environment.