$ git clone -n https://src.fedoraproject.org/rpms/calcium-calculator.git /var/lib/mock/f40-build-797444-141349/root/chroot_tmpdir/scmroot/calcium-calculator
Cloning into '/var/lib/mock/f40-build-797444-141349/root/chroot_tmpdir/scmroot/calcium-calculator'...
$ git fetch origin c3efe364f930e235c7d2a32f2df8c03c10a376a2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/calcium-calculator
 * [new ref]         c3efe364f930e235c7d2a32f2df8c03c10a376a2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c3efe36 Add Packit config