Best Practices

These guides collect operational advice for writing NixOS tests that are fast to debug, robust in CI, and portable across different environments.

• Always set timeouts

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  Use global and per-operation timeouts so broken tests fail quickly instead of burning CI time.

• Avoid race conditions

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  Wait for the right units and ports before asserting on a service.

• Use parallelism across machines

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  Start long-running setup on all nodes first, then wait for completion so multi-node tests do not serialize unnecessary work.

• Use the right pkgs attribute

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  Keep host packages and guest packages separate so tests stay portable.