@yonkoc thanks for confirming the issue with UpCloud and provide a (potential) fix. I have emailed UpCloud support about, as follows (providing the needed links) :
Dear Sirs,
Knowing Mail-in-a-Box deploys perfectly over DigitalOcean, Linode, Vultr... etc I spent long time trying to install Mail-in-a-box (github) mail server in your platform over your Ubuntu 18.04 LTS provided image but hangs half the way of the installation script ...
The issue has been told in this post at their forum, and seems finally the user @yonkoc got to debug why this happens and looks like, at least, your provided Ubuntu 18.04 LTS image has been provisioned without a specified locale then, the needed patch is to have setup its default locale as follows:
locale-gen en_US.UTF-8
update-locale LANG=en_US.UTF-8
>> I would like you to FIX your provided images ASAP.
Thanks in advance for your attention / feedback,
best.
- I hope they will answer / fix it soon. I’d post again here if a feedback arrives.