func TestCPUProfileDupFrameInlining(t *testing.T) {
	var stk [32]uintptr
	matches := matchAndAvoidStacks(stackContains, []string{"runtime.pcvalue"}, avoidFunctions())
	p := testCPUProfile(t, matches, func(dur time.Duration) {
		cpuHogger(func(i int) int {
			_ = runtime.Callers(0, stk[:])
			return i
		}, &salt1, dur)
	})

	for _, sam := range p.Sample {
		var stack []string
		var bad string
		for _, loc := range sam.Location {
			for _, line := range loc.Line {
				name := fmt.Sprintf("%s:%d", line.Function.Name, line.Line)
				if len(stack) != 0 && name == stack[len(stack)-1] {
					bad = name
				}
				stack = append(stack, name)
			}
		}
		if bad != "" {
			t.Logf("found repeated function entry %q in stack %q", bad, stack)
			if strings.HasPrefix(bad, "runtime.pcvalue:") {
				// The profile may show legitimate recursive functions, but we
				// know that runtime.pcvalue does not call itself and so should
				// not appear to in the profile.
				t.Fail()
			}
		}
	}
}

found repeated function entry "runtime.pcvalue:932" in stack ["runtime.fastrand:135" "runtime.fastrandn:157" "runtime.pcvalue:932" "runtime.pcvalue:932" "runtime.pcdatavalue:1076" "runtime.gentraceback:364" "runtime.callers.func1:914" "runtime.systemstack:233" "runtime.callers:913" "runtime.Callers:237" "runtime/pprof.TestCPUProfileDupFrameInlining.func1.1:343" "runtime/pprof.cpuHogger:41" "runtime/pprof.TestCPUProfileDupFrameInlining.func1:342" "runtime/pprof.testCPUProfile:497" "runtime/pprof.TestCPUProfileDupFrameInlining:341" "testing.tRunner:1449"]