When using the `TAIL' environment, the tail(1) process
inherits the non-FD_CLOEXEC pipe we introduced in commit
5f9baf725106 (t/httpd-unix: eliminate some busy waits, 2022-12-12).
We must ensure that pipe is gone before waiting on -httpd's
death by destroying the tail(1) process, first.
my $pid = $read_pid->($pid_file);
is(kill('TERM', $pid), 1, "signaled daemonized $w process");
vec(my $rvec = '', fileno($p0), 1) = 1;
+ delete $td->{-extra}; # drop tail(1) process
is(select($rvec, undef, undef, 1), 1, 'timeout for pipe HUP');
is(my $undef = <$p0>, undef, 'process closed pipe writer at exit');
ok(!-e $pid_file, "$w pid file unlinked at exit");