$ git clone -n https://src.fedoraproject.org/rpms/osbuild.git /var/lib/mock/f42-build-side-1-3537691-46560/root/chroot_tmpdir/scmroot/osbuild
Cloning into '/var/lib/mock/f42-build-side-1-3537691-46560/root/chroot_tmpdir/scmroot/osbuild'...
$ git fetch origin a7e03070d70ada1ee026647a86f0d633d55e2308:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/osbuild
 * [new ref]         a7e03070d70ada1ee026647a86f0d633d55e2308 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a7e0307 Update to 151 upstream release