Hi James,
I've not seen that error before, but I did manage to find this thread, which has an explanation and possible solution for that problem:
You could make a backup of your sources list before retrying the upgrade, and then reapplying it afterwards. I've also found a gist with the default Ubuntu 18.04 sources list here:
Regarding AtoM not working:
I will follow up with our team for further suggestions since I'm not a system administrator, but I'll try to offer a few initial thoughts.
Elasticsearch is necessary for providing search and browse page results, so it definitely could be related. Try re-enabling that source and restarting Elasticsearch to see if it helps.
If not, then my first suggestion would be to check the Nginx webserver (particularly the config file
created during installation at
/etc/nginx/sites-available/atom), try reloading it
(sudo systemctl reload nginx), and also check for any error messages in the logs:
Of course, AtoM 2.4 was never tested on Ubuntu 18.04, and there are a number of other differences in the underlying dependencies - for example:
- 2.4 uses PHP 7.0 when running Ubuntu 16.04; 2.6 expects PHP 7.2
- 2.4 used a manually installed php-apcu_bc-beta package because php-apcu was not available in Ubuntu 16.04 at the time. 2.6 can just use php-apcu.
- 2.4 uses Elasticsearch 1.7, while 2.6 uses v5.6
- 2.4 uses MySQL 5.6, while 2.6 uses v8.0
- etc...
It may be that there is some underlying conflict with the Ubuntu version and the 2.4 dependencies, and that you might just need to do the Ubuntu upgrade at a time when you can immediately work on a new AtoM installation and accept some downtime for your site as you transition - or ideally, set it up in a new VM and then just update the DNS record to point to the new virtual server once you have AtoM 2.6 running.
I did manage to talk to one AtoM developer still working this afternoon, who basically agreed with this last point.
I would fall back to our recommended upgrade procedure, i.e. set up a new Ubuntu 18.04 VPS, install AtoM 2.6 according to the installation instructions, migrate and upgrade your database data, and copy over the digital objects, etc. Checking the error logs will hopefully expose the immediate error that is breaking the site, but I expect it may be a rabbit warren of dependency issues and incompatible software versions. Unfortunately, in-place upgrade is generally not the shortcut it looks to be.
So.... with those warnings in mind, start with the suggestions here, and let us know how it goes. If you find anything useful in the webserver error logs but are unsure how to proceed, feel free to share it here, and we'll try to offer further suggestions if we're able. Good luck!