stack "Error parsing targets" in CI

By Daniel Zoghalchali·Latchkey

stack could not interpret a target you asked it to build or test. The package, component, or path on the command line does not match anything in the project.

What this error means

stack build/test exits with Error parsing targets: followed by the unrecognized target. It is deterministic and tied to your command and stack.yaml.

Error parsing targets: Unknown local package: myapp-tests

The valid targets are:
  myapp
  myapp:test:myapp-test

Common causes

Wrong package or component name

The target name does not match a package in stack.yaml or a component in the cabal file (a typo or wrong suffix).

Package not in stack.yaml packages

A package directory is not listed under packages:, so stack does not know about it.

How to fix it

Use a valid target name

List what stack recognizes, then build that.

stack ide targets
stack test myapp:test:myapp-test

Register the package in stack.yaml

1. Add the package directory under packages:.
2. Confirm the cabal file names the component you target.
3. Re-run after editing stack.yaml.

How to prevent it

• Reference exact component names in CI.
• Keep stack.yaml packages list complete.
• Use stack ide targets to discover valid names.

Frequently asked questions

Related guides

References

• GitHub Actions documentation