$ git clone -n https://src.fedoraproject.org/rpms/rust-git2-curl.git /var/lib/mock/f40-build-2061995-49167/root/chroot_tmpdir/scmroot/rust-git2-curl
Cloning into '/var/lib/mock/f40-build-2061995-49167/root/chroot_tmpdir/scmroot/rust-git2-curl'...
$ git fetch origin 6e815f5fb5082894502be1b0c828c184f4cf5808:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-git2-curl
 * [new ref]         6e815f5fb5082894502be1b0c828c184f4cf5808 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6e815f5 Update to version 0.19.0; Fixes RHBZ#2059246