$ git clone -n https://src.fedoraproject.org/rpms/rust-rustfix.git /var/lib/mock/f45-build-44562-815/root/chroot_tmpdir/scmroot/rust-rustfix
Cloning into '/var/lib/mock/f45-build-44562-815/root/chroot_tmpdir/scmroot/rust-rustfix'...
$ git fetch origin 14598b1506d3ef1116d19288d572299a7c7a113c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rustfix
 * [new ref]         14598b1506d3ef1116d19288d572299a7c7a113c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 14598b1 Update to version 0.9.7; Fixes RHBZ#2459437