$ git clone -n https://src.fedoraproject.org/rpms/rust-gufo-jpeg.git /var/lib/mock/f45-build-42153-791/root/chroot_tmpdir/scmroot/rust-gufo-jpeg
Cloning into '/var/lib/mock/f45-build-42153-791/root/chroot_tmpdir/scmroot/rust-gufo-jpeg'...
$ git fetch origin a24203ed84d3f51a78c99741fbbb0fca3b8478be:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gufo-jpeg
 * [new ref]         a24203ed84d3f51a78c99741fbbb0fca3b8478be -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a24203e Update to version 0.5.1; Fixes RHBZ#2529501