Fedora upgrade code relies on pkgdb 'collections' API, which is being retired
Submitted by Adam Williamson
The code which determines which Fedora releases are available as upgrades - plugins/fedora-pkgdb-collections/gs-plugin-fedora-pkgdb-collections.c in current git master - relies on the pkgdb 'collections' API endpoint:
However, pkgdb is being retired. At present it's read-only and has been since August 4th, so the data it contains is inaccurate: it still considers Fedora 24 active (it is in fact EOL) and does not know that Fedora 27 has been branched. At some point soon, it will likely go away entirely.
The idea is that code should switch to using PDC - https://pdc.fedoraproject.org/ - for this instead. However, there's a major problem with that: PDC doesn't distinguish between development and stable releases, it only has 'active' and 'inactive' (EOL). So both Fedora 26 and Fedora 27 (which has just branched) are listed as 'active', which is obviously no good for gnome-software's needs.
There has been an issue open on this for a long time: https://github.com/product-definition-center/product-definition-center/issues/294
I've poked Ralph Bean to give it some urgency. Note, we will need to ship updates for all supported Fedora releases once this can be fixed...