autopkgtests fail in armhf with sudo: no tty present and no askpass program specified

[Leo Arias]

Failed log:
https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-xenial/xenial/armhf/s/snapcraft/20160226_194542@/log.gz

[Leo Arias (elopio)]

<elopio> ping pitti: our autopkgtests on armhf are failing because: "sudo: no tty present and no askpass program specified". But they pass in amd64.
<elopio> Do you know what's different in the testbeds?
<pitti> elopio: armhf and s390x run in LXC, the other three arches in a full VM (in ova)
<pitti> "nova"
<pitti> elopio: if you have to call sudo in a test, please always call it with -n, to avoid blocking indefinitiely
<pitti> and use SSH_ASKPASS
<pitti> (this is usually already set in the test env, but you might change the environment)
<elopio> pitti: ack. I'll get a lxc tomorrow to give it a try.

[Sergio Schvezov (sergiusens)]

|-- sergiusens@lindon:~/source/github.com/ubuntu-core/snapcraft (master *) --|
$ lxc exec acanthous-arely -- sudo -iu sergiusens
To run a command as administrator (user "root"), use "sudo <command>".
See "man sudo_root" for details.

sergiusens@acanthous-arely:~$ ls
sergiusens@acanthous-arely:~$ mkdir s
sergiusens@acanthous-arely:~$ cd s
sergiusens@acanthous-arely:~/s$ vim snapcraft.yaml
sergiusens@acanthous-arely:~/s$ snapcraft
Installing build dependencies: python3-setuptools python3-dev
sudo: no tty present and no askpass program specified
Command '['sudo', 'apt-get', '-o', 'Dpkg::Progress-Fancy=1', '--no-
install-recommends', '-y', 'install', 'python3-setuptools',
'python3-dev']' returned non-zero exit status 1