     struct PartialTestConfig {
       var delim: String?
       var tags, skipTags: Set<BenchmarkCategory>?
-      var numSamples: Int?
+      var numSamples: UInt?
       var fixedNumIters: UInt?
       var afterRunSleep: UInt32?
       var sampleTime: Double?

    delim = c.delim ?? ","
    sampleTime = c.sampleTime ?? 1.0
    fixedNumIters = c.fixedNumIters ?? 0
    numSamples = c.numSamples ?? 1
    verbose = c.verbose ?? false
    logMemory = c.logMemory ?? false
    afterRunSleep = c.afterRunSleep

    let p = ArgumentParser(into: PartialTestConfig())
    p.addArgument("--num-samples", \.numSamples,
                  help: "number of samples to take per benchmark; default: 1",
                  parser: { UInt($0) })
    p.addArgument("--num-iters", \.fixedNumIters,
                  help: "number of iterations averaged in the sample;\n" +
                        "default: auto-scaled to measure for `sample-time`",
