<p>
Package initialization&mdash;variable initialization and the invocation of
<code>init</code> functions&mdash;happens in a single goroutine,
sequentially, one package at a time.
An <code>init</code> function may launch other goroutines, which can run
concurrently with the initialization code. However, initialization
always sequences
the <code>init</code> functions: it will not invoke the next one
until the previous one has returned.

<p>
Package initialization&mdash;variable initialization and the invocation of
<code>init</code> functions&mdash;happens in a single goroutine,
sequentially, one package at a time.
An <code>init</code> function may launch other goroutines, which can run
concurrently with the initialization code. However, initialization
always sequences
the <code>init</code> functions: it will not invoke the next one
until the previous one has returned.

	}
	if runtime.GOOS == "linux" {
		if _, err := os.Stat("/etc/alpine-release"); err == nil {
			t.Skip("skipping failing test on alpine - go.dev/issue/19938")
		}
	}

	// Launch some threads in C.
	const cts = 5
	C.trial(cts)
	defer C.cleanup()

	vs := []struct {
		call           string
		fn             func() error
		filter, expect string
	}{