     let p = ArgumentParser(into: PartialTestConfig())
     p.addArgument("--num-samples", \.numSamples,
                   help: "number of samples to take per benchmark; default: 1",
-                  parser: { Int($0) })
+                  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`",

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

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