Actually, I have never gotten the impression that building from source is unsupported.
It is officially recommended that you save yourself the time and use the precompiled binaries,
obviously, but if those don't work because of incompatibilities with whatever Ubuntu did now, then I regard building from source as an eminently reasonable alternative.
The only thing I have seen Kovid warn strongly against, is using distro compiled versions... for the simple reason that most distros seem to have a weird compulsion to remove bits of calibre they disagree with.
(Okay, so the Download Linux page has a scary red warning.
As far as I am concerned that is just a basic #include "stddisclaimer.h" to keep the riffraff away.)
I think the main two (replaced by incompatible copies) are:
The
forked and heavily modified html5lib, which is critical to converting books and is fundamentally incompatible with the original upstream html5lib project.
Or cherrypy (used in the content server) which has a bug which makes it unsuitable for bundling inside another application, a bug that has gone unfixed upstream
for years, and calibre now ships a fixed copy. The content server also won't allow mobile devices to connect with a password when using upstream cherrypy...
Special mention goes to debian and echoed by Ubuntu, for disabling the plugin updater for "security concerns".
And for disabling CBR comics for political reasons.
...
For obvious reasons, building from source and replacing these two bundled modules is an excellent way to get your bug report ignored.
But I have gotten and seen other bug reports accepted, and Kovid was happy to help -- I always use calibre built from source (see the Arch Linux "calibre-git" package with my name on it
).
...
If calibre 2.48 works fine, there is no need to upgrade. Many people only upgrade when they need a new feature, and that is a very valid thing to do! Don't fix what ain't broke...
But if you decide you really need something in a newer version, I think you will be able to find help, so long as you follow the official instructions for a source install.
