Question: Perl is giving me an undef value when I access a variable that is supposed to be defined in the **%ENV** hash. How is this possible?

```
root@23cd5f45def7:~/bin$ perl -e 'warn $ENV{SHELL}'
Warning: something's wrong at -e line 1.

```

I would expect perl to output **/bin/bash** instead. 

More info on the environment:

```
root@23cd5f45def7:~/bin$ echo $SHELL
/bin/bash

root@23cd5f45def7:~/bin$ $SHELL --version
GNU bash, version 4.2.37(1)-release (x86_64-pc-linux-gnu)
Copyright (C) 2011 Free Software Foundation, Inc.
...

root@23cd5f45def7:~/bin$ perl -v

This is perl 5, version 14, subversion 2 (v5.14.2) built for x86_64-linux-gnu-thread-multi
(with 91 registered patches, see perl -V for more detail)
...

```

I am running this on Debian wheezy in a docker container.

The image was created with 

```
sudo debootstrap wheezy ../_build  http://ftp.us.debian.org/debian
sudo tar -C ../_build -c . | docker import - wheezy/bootstrap

```

I get the same beheviour with perl-5.24.1 compiled manually from sources.

Answer: 
The ListView doesn't have the nested scrolls enabled by default. Use

```
ViewCompat.setNestedScrollingEnabled(listView, true);

```

to enable it. 

Be aware that this will from from lollipop onwards . If you want to support older versions of android you should use a RecyclerView
**`ListView` doesn't support nested scrolling**
Use `RecyclerView` instead of `ListView` and enable nested scrolling in `RecyclerView`