$ git clone -n https://src.fedoraproject.org/rpms/rust-rxml_proc.git /var/lib/mock/f39-build-1527345-36143/root/chroot_tmpdir/scmroot/rust-rxml_proc
Cloning into '/var/lib/mock/f39-build-1527345-36143/root/chroot_tmpdir/scmroot/rust-rxml_proc'...
$ git fetch origin 7ef610f4db3d847b3e2dea7d9b991aaad4b05245:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rxml_proc
 * [new ref]         7ef610f4db3d847b3e2dea7d9b991aaad4b05245 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7ef610f Update to version 0.9.1; Fixes RHBZ#2164391