gnu screen does not work in classic?

[Dan Kegel]

I tried to use 'screen' as usual to start a long-running job
inside classic, but it failed because /proc/self/fd/0 was
owned by root:

$ ssh user at host
Welcome to Ubuntu Core 16 (GNU/Linux 4.4.0-1030-raspi2 armv7l)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage
Welcome to Snappy Ubuntu Core, a transactionally updated Ubuntu.

 * See https://ubuntu.com/snappy

It's a brave new world here in Snappy Ubuntu Core! This machine
does not use apt-get or deb packages. Please see 'snap --help'
for app installation and transactional updates.

Last login: Tue Jan  3 00:06:36 2017 from 10.10.150.120
user at host:~$ sudo classic
mount: devpts is already mounted or /dev/pts busy
       devpts is already mounted on /dev/pts
(classic)user at host:~$ ls -lL /proc/self/fd/0
crw------- 1 root root 136, 1 Jan  3 00:08 /proc/self/fd/0
(classic)user at host:~$ screen
Cannot open your terminal '/dev/pts/1' - please check.
(classic)user at host:~$ ls -l /proc/self/fd/0
lrwx------ 1 user user 64 Jan  3 00:08 /proc/self/fd/0 -> /dev/pts/1
(classic)user at host:~$ ls -l /dev/pts/1
crw------- 1 root root 136, 1 Jan  3 00:08 /dev/pts/1