$ git clone -n https://src.fedoraproject.org/rpms/rubygem-crass.git /var/lib/mock/f45-build-34884-692/root/chroot_tmpdir/scmroot/rubygem-crass
Cloning into '/var/lib/mock/f45-build-34884-692/root/chroot_tmpdir/scmroot/rubygem-crass'...
$ git fetch origin 65dc9419182d5d9cb1e547e24172950c1ee45fb0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-crass
 * [new ref]         65dc9419182d5d9cb1e547e24172950c1ee45fb0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 65dc941 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild