I tried enabling fragments on the autobuilder. I started with two fragments, one had a BB_CONF_FRAGMENT_SUMMARY (no description) and one did not. When I started a build having enabled the fragment without the summary by setting OE_FRAGMENTS += "xxx", I see the failure: ERROR: Could not find fragment yocto-autobuilder/autobuilder in enabled layers: when I instead run bitbake-config-build list-fragments, it tells me to add the summary, which is a much more useful message. Curiously, if I add two fragments and one has the summary, that fixes the issue which is likely a second issue we need to address too.
It turns out I was missing the layer prefix so the fragment wasn't configured. What puzzles me is why some builds with this configured were not erroring in some cases, e.g.: https://valkyrie.yoctoproject.org/#/builders/10/builds/763/steps/10/logs/stdio has: OE_FRAGMENTS += 'yocto-autobuilder/autobuilder' yet the build is proceeding? I'd note the config tool also errored with the description missing once I fixed the short logs. The config tool doesn't like adding require conf/multilib.conf to a fragment.
The conf/multilib.conf issue also appears in an oe-selftest failure of bblayers.BitbakeConfigBuild.test_enable_disable_fragments https://valkyrie.yoctoproject.org/#/builders/76/builds/727/steps/15/logs/stdio
I sent a patch for the multilib issue. There seem to be other issues here, but I am not sure how to reproduce and observe them. Can I trigger something on the autobuilder against some branches you made, or maybe there are steps I can take locally?
conf/multilib issue is fixed. Richard plans to add more info when he is in a more coherent state. ;-)