$ git clone -n https://src.fedoraproject.org/rpms/rubygem-image_processing.git /var/lib/mock/f45-build-34992-692/root/chroot_tmpdir/scmroot/rubygem-image_processing
Cloning into '/var/lib/mock/f45-build-34992-692/root/chroot_tmpdir/scmroot/rubygem-image_processing'...
$ git fetch origin b26426a02f2624982c1787d87987272d485bc077:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-image_processing
 * [new ref]         b26426a02f2624982c1787d87987272d485bc077 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b26426a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild