Nightly: su requires a full pty

su user -c "..." used to work well in alpha 4, such as over ssh, for running privileged commands. Now in nightly, su requires a full pseudo terminal environment or else exits with a message like:

su: Refused login. Setting up environment failed: Invalid Argument

This is annoying. As a workaround, Packer can synthesize a pty with ssh_pty: true, though is is not ideal.

Noticed this by chance and so fixed it in hrev52300. In the future, if you don’t want these to get lost, please open tickets on the bugtracker.