Re: [PATCH 2/3] test-lib: show leak-sanitizer logs on --immediate failure

> When we've compiled with SANITIZE=leak, at the end of the test script
> we'll dump any collected logs to stdout. These logs have two uses:
> 
>   1. Leaks don't always cause a test snippet to fail (e.g., if they
>      happen in a sub-process that we expect to return non-zero).
>      Checking the logs catches these cases that we'd otherwise miss
>      entirely.
> 
>   2. LSan will dump the leak info to stderr, but that is sometimes
>      hidden (e.g., because it's redirected by the test, or because it's
>      in a sub-process whose stderr goes elsewhere). Dumping the logs is
>      the easiest way for the developer to see them.
> 
> One downside is that the set of logs for an entire script may be very
> long, especially when you're trying to fix existing test scripts. You
> can run with --immediate to stop at the first failing test, which means
> we'll have accrued fewer logs. But we don't show the logs in that case!
> 
> Let's start doing so. This can only help case (2), of course (since it
> depends on test failure). And it's somewhat weakened by the fact that
> any cases of (1) will pollute the logs. But we can improve things
> further in the next patch.