Don't try to treat Windows specially. It's a bit hopeless.

bin/cp

@@ -50,16 +50,7 @@ sub run {
 	my( $source, $destination ) = @args;
 
 	my @unix_like = qw(darwin freebsd linux);
-	if( $^O eq 'MSWin32' ) {
-		# https://home.csulb.edu/~murdock/copy.html
-		my @command = 'copy';
-		push @command, '/-Y' if $opts{i};
-		push @command, $source, $destination;
-
-		print "cp $source $destination\n" if $opts{v};
-		my $rc = system { $command[0] } @command
-		}
-	elsif( grep { $^O eq $_ } @unix_like and in_path('cp') ) {
+	if( grep { $^O eq $_ } @unix_like and in_path('cp') ) {
 		# Although File::Copy seems like it should do the right thing,
 		# it doesn't.
 		my @command = 'cp';