I recommend 19.10. gcc is at 9.2.1, which seems to have pushed through a lot of deprecations. The foundational image libraries, jpeg, tiff, and png, are at current major versions.
Ah, you have a server you’re responsible for. I’ve got a VPS, LTS at 18.04, but that’s a very different application with almost no overlap in dependencies with my workstation. As long as they’re posting security updates for both, I’m not worried about the version difference…
Packages for 3.0.0 for several distributions are available under the following link:
https://software.opensuse.org/download.html?project=graphics:darktable&package=darktable
I followed the instructions for Fedora 31 but got the response:
Package darktable-2.6.3-2.fc31.x86_64 is already installed.
Inserting a:
dnf erase fedora
proved to be necessary
I know dnf is just horrible, that’s why I use zypper on Fedora. Try to install it with:
dnf install darktable --allowerasing --best
Anyway, now it is installed, I think I should have waited for the new user manual.
But I seem to recall that someone posted some links to videos here for upgrading the user, so I’ll see if I can find them.
I just follow your link but I still see 2.6.2 on this link. Is there a problem ?
Edit, only darktable 3.0 packages for Fedora and OpenSuse are available (except for Leap 42.3) but still on 2.6.2 for Debian and Ubuntu. 2.6.3 on similar stable link but no 3.0.0.
I think the debian stuff needs to be updated, but it packaged 3.0.0:
[ 221s] Debian archive chosen for transformation: debian.tar.xz
[ 221s] converting //usr/src/packages/SOURCES/darktable-3.0.0.tar.xz to darktable-3.0.0.tar.gz
[ 222s] Moving //usr/src/packages/SOURCES/darktable-3.0.0.tar.gz to //usr/src/packages/SOURCES.DEB/darktable_2.6.2.orig.tar.gz
The Debian package has been uploaded to Debian experimental shortly before the new year and compiles well at least back until buster.
Hi Francis! Could you please briefly explain how you installed dt3 using the nix package manager? I’m also using (k)ubuntu 16.04, and I haven’t found a way to get the version 3 so far (and I would prefer not to upgrade the ubuntu version at this moment)
In a terminal:
curl https://nixos.org/nix/install | sh
nix-env -i darktable
darktable &
Thanks! It worked!
Minor tip: so that you can do everything in one shot (loading the nix environment without having to log out and back in after installing), I recommend:
# Install nix
curl https://nixos.org/nix/install | sh
# Load nix environment
. ~/.nix-profile/etc/profile.d/nix.sh
# Install darktable
nix-env -i darktable
# Run darktable
darktable &Hello, and thank you for this program I’m trying to learn.
Probably I have missed something, but I’ve tried to upgrade from 2.6.3 in Windows and after installing new version I just get
========================================
version: darktable 3.0.0
start: 2020:01:15 19:54:02
What can I do?, apart from crying 
Thank you
Hey @Alemi_Photo, welcome! Do you have experience working with databases at all? You can try and dump your database and reimport it using the sqlite cm and line tools.
Or you can try and repair the database in some automatic way.
Whatever happens, make a backup of your database now!
This is coming from a check in the migration process.
This looks like an SQLite3 error message. This is clear, the library.db database is corrupted.
The only possible conclusion 
The only hope you have it to have a non too old backup of the library which is not corrupted.
The only backup I have is just before migrating, so I think I would have the same problem.
But I have no messages about this corruption before migrating 
What are your suggestions then?
Thank you @paperdigits,
Yes I have some experience with mysql, but not with sqlite. Is there any procedure available? I’ll check anyway.
Which is that automatic way?
Thank you very much indeed
Because the migration (especially this one) goes through all the table and almost all the data and maybe there is only part of the db which is corrupted.
Already given, but since you don’t have another backup… You may have to re-import everything in a new database.
Thank you @Pascal_Obry ,
I have used DB “Browser for SQLite”, exported to SQL, imported to a new DB, replaced and, voilà! migration completed and, aparently, all my pictures are ready!!
Thank you very much for your help!!