Hello Tobias,
This error was likely caused by the core-updates-frozen-batched-changes specification removal in Cuirass. Some builds keep referring to removed specifications causing unexpected behaviours. The strange thing is that I'm using the "DELETE CASCADE" SQL property that should remove Builds pointing to a removed specification automatically. Regardless of this misunderstanding, it might not be great idea to remove specifications altogether because a build that is added by the core-updates-frozen specification might be referred by the master specification once the merge has happened. I introduced specification deactivation with https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git/commit/?id=b362f06b9134f99a476e0f2ec32335ce6ddc6e8c to work around this problem. This is not yet deployed, but I think it should solve the issue you reported. Thanks, Mathieu
