$ git clone -n https://src.fedoraproject.org/rpms/rust-num-bigint-dig.git /var/lib/mock/f45-build-43483-803/root/chroot_tmpdir/scmroot/rust-num-bigint-dig
Cloning into '/var/lib/mock/f45-build-43483-803/root/chroot_tmpdir/scmroot/rust-num-bigint-dig'...
$ git fetch origin 3cf369fe470b814dfc8bd3580a84e400b8dba482:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-num-bigint-dig
 * [new ref]         3cf369fe470b814dfc8bd3580a84e400b8dba482 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3cf369f Update to version 0.9.1; Fixes RHBZ#2412625