$ git clone -n https://src.fedoraproject.org/rpms/rust-tracker.git /var/lib/mock/f45-build-45616-824/root/chroot_tmpdir/scmroot/rust-tracker
Cloning into '/var/lib/mock/f45-build-45616-824/root/chroot_tmpdir/scmroot/rust-tracker'...
$ git fetch origin 0cce613638c9360bc7c0a7622a17825b364f8f57:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tracker
 * [new ref]         0cce613638c9360bc7c0a7622a17825b364f8f57 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0cce613 Update to 0.2.3 (fedora#2493938).