}
 
 sub _destroy {
-       my ($self, $rbuf, $in, $out, $pid, $err) = @_;
-       delete @$self{($rbuf, $in, $out)};
-       delete $self->{$err} if $err; # `err_c'
+       my ($self, $pid, @rest) = @_; # rest = rbuf, in, out, err
+       my ($p) = delete @$self{($pid, @rest)};
 
        # GitAsyncCat::event_step may delete {$pid}
-       my $p = delete($self->{$pid}) // return;
-       awaitpid($p) if $$ == $self->{"$pid.owner"};
+       awaitpid($p) if defined($p) && $$ == $self->{"$pid.owner"};
 }
 
 sub async_abort ($) {
        async_wait_all($self);
        delete $self->{inflight};
        delete $self->{inflight_c};
-       _destroy($self, qw(rbuf in out pid));
-       _destroy($self, qw(rbuf_c in_c out_c pid_c err_c));
+       _destroy($self, qw(pid rbuf in out));
+       _destroy($self, qw(pid_c rbuf_c in_c out_c err_c));
        undef;
 }