The [SetCrashOutput] function allows the user to specify an alternate
file to which the runtime should write its fatal crash report.
It may be used to construct an automated reporting mechanism for all
unexpected crashes, not just those in goroutines that explicitly use

</p>

<p>
If the channel were buffered (e.g., <code>c = make(chan int, 1)</code>)
then the program would not be guaranteed to print
<code>"hello, world"</code>.  (It might print the empty string,
crash, or do something else.)
</p>

<p class="rule">
The <i>k</i>th receive on a channel with capacity <i>C</i> is synchronized before the completion of the <i>k</i>+<i>C</i>th send from that channel completes.
</p>