$ git clone -n https://src.fedoraproject.org/rpms/rust-grep-cli.git /var/lib/mock/f39-build-1521714-35856/root/chroot_tmpdir/scmroot/rust-grep-cli
Cloning into '/var/lib/mock/f39-build-1521714-35856/root/chroot_tmpdir/scmroot/rust-grep-cli'...
$ git fetch origin 0b13e028683d88dfb973277dfa29379a7ae235f7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-grep-cli
 * [new ref]         0b13e028683d88dfb973277dfa29379a7ae235f7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0b13e02 Update to version 0.1.9; Fixes RHBZ#2223734