my $HAVE_Capture_Tiny = 0;
eval "use Capture::Tiny qw(capture)";
if ( !$@ ) {
    $HAVE_Capture_Tiny = 1;
}

...

if ( $HAVE_Capture_Tiny ) {
    my $c = Capture::Tiny->new( ... );
} else {
   ## fallback if not have Capture::Tiny
}