$ git clone -n https://src.fedoraproject.org/rpms/crash-gcore-command.git /var/lib/mock/f42-build-3449843-45479/root/chroot_tmpdir/scmroot/crash-gcore-command
Cloning into '/var/lib/mock/f42-build-3449843-45479/root/chroot_tmpdir/scmroot/crash-gcore-command'...
$ git fetch origin b01bd5bfb863912b451b36084a6f311fb2d65fc7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/crash-gcore-command
 * [new ref]         b01bd5bfb863912b451b36084a6f311fb2d65fc7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b01bd5b Version 1.6.4-7