Execution

Conditions narrow; settings override

Every condition on a stage must pass. Use one whenAny block when either condition should enable it:

open Partas.Build

let publish = stage "publish" {
    whenBranch "master"
    whenWindows
    run "dotnet pack"
}

This stage runs on Windows and master. A second condition never replaces the first. Supply a reason to when' so --explain can describe a skip.

Settings such as workingDir and parallel' use the last value at the same level. A child stage inherits unset settings from its parents and pipeline. Command settings fill in pipeline defaults.

Run independent work concurrently

let compile = stage "compile" {
    parallel' 2
    run "dotnet build A.fsproj"
    run "dotnet build B.fsproj"
    run "dotnet build C.fsproj"
}

At most two steps run at once. Omit parallel' for sequential execution; use parallel' true for unbounded concurrency. Avoid parallel builds that write the same referenced project's outputs.

Bound execution time

let test = stage "test" {
    timeout 60
    timeoutForStep 30
    run "dotnet test"
}

A timeout cancels the stage and kills its process tree. Pipelines additionally support timeoutForStage. A blocking F# function must cooperate with cancellation itself.

Always clean up

let integration = pipeline "integration" {
    stage "start" { run "docker compose up -d" }
    stage "test" { run "dotnet test" }
    post [ stage "stop" { run "docker compose down" } ]
}

Post stages run after the main stages, including after failure.

Decide how failure propagates

• continueStepsOnFailure: run the remaining steps.
• continueStageOnFailure: let the pipeline continue.
• continueOnStepFailure: apply both.
• acceptExitCodes: accept additional process exit codes.
• failIfIgnored: treat a skipped stage as failure.

For typed outputs and prerequisite ordering, use producers and dependencies. For recovery policies, see failure handlers.