just my contribution to the topic........
I installed Calibre 3.7 on a Debian Stretch server with rather old hardware but decent processor (dual core) and ram (4+ Gb).
Then from an OSX terminal (XQuartz installed) I logged in to the server with ssh.
Then started calibre on the Debian server.
It takes some time, but then I get the familiar screens of the calibre application, the splash screen was a mess so I disabled it.
Calibre/Debian throws the following error, but all seems to function as expected. It just explains why it takes some time (up to a minute) before calibre shows up.
Code:
ERROR:dbus.proxies:Introspect error on :1.3:/org/freedesktop/NetworkManager: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.