Some of the rpmgrill runs (e.g. [1]) started to fail with
'build.log.aarch64' -> 'unpacked/aarch64/build.log' mv: cannot move 'build.log.aarch64' to 'unpacked/aarch64/build.log': No such file or directory
Turned out we forgot to change the method that downloads koji build logs to work with supported_archs. This patch fixes that.
[1] http://taskotron-dev.fedoraproject.org/taskmaster/builders/x86_64/builds/280195